All language subtitles for m.f.a.s02e02.1080p.web.h264-cbfm_track3_[eng]

NARRATOR: A burning giant,
torching everything in its path.

- What has created this
flaming cloud of oblivion?

NARRATOR: Disaster strikes a
treasured forest

near a mythical
mountain lake.

- This landscape looks apocalyptic!

NARRATOR: A threatening radioactive
area comes back to life.

- This does not make sense.

NARRATOR: And an ancient
icon disappears.

- It looks like it was
just vaporized.

NARRATOR: Everywhere we look
on our planet,

there's evidence of the past.

In nature...

in buildings...

in relics.

Each holds a mystery that technology
now allows us to see from above.

What new secrets are revealed?

Since time began, disasters are
something that human civilizations

have always struggled to comprehend.

But sometimes, the best way
to understand a disaster

is to decipher it from above.

Nestled in the shadow of
Northern California's mountains,

just outside city of Redding,

the view from above reveals
a terrifying sight.

MAN: (on video) Oh my God!

- It honestly looks like the
gates of hell have opened.

- It looks like the earth is opening
up and it's barfing out fire.

NARRATOR: But there's something
strange about this fire.

- The flames and smoke are behaving
in a way that are very peculiar.

- I'm absolutely terrified.

It's literally spiralling
out of control.

- What on earth has created this
flaming cloud of oblivion?

NARRATOR: In July of 2018,

just 20 kilometres west
of Redding, California,

a massive wildfire broke out
and bore down on the city.

- The fire was burning
for three or four days.

It was around 20,000 acres
when it finally hit Redding.

NARRATOR: The colossal blaze burned
through the west side of Redding

to the edge of the Sacramento River.

High winds sent embers
flying across the water,

spreading the fire before many
of the residents could escape.

RALEY: The fire spread was so rapid

that it made it difficult for
residents to get out in time.

And very quickly became apparent

that we were, sort of,
in a grave situation.

KOUROUNIS: Inside Redding,
the massive wall of flames

created temperatures up to
2,700-degrees Fahrenheit,

hot enough to melt steel.

NARRATOR: Even more incredible,
a churning vortex of fire appeared,

1,000 feet wide and towering almost
18,000 feet into the dark sky.

- The size of this blaze is
mind-blowing.

But it's twisting.
So, what's happening here?

- When I see a fire of this size
with these immense plumes of smoke,

my first thought is, was
this some kind of explosion?

NARRATOR: Could
an explosion be behind

this terrifying tower of flame?

Perhaps there's a clue thousands of
kilometres away in Beirut, Lebanon,

where a massive blast
shook the city in 2020.

Here, a port storing almost 3,000
tonnes of ammonium nitrate

caught fire, triggering a disaster.

- The fire apparently spread
to some fireworks

that were being stored on the site

and then there was
this huge explosion...

..that resulted in massive plumes
of smoke that stretched

more than 700 metres into the air.

GUY: The shockwave caused
over 200 casualties

and was felt over
a hundred miles away.

- Who can forget that explosion?

I mean, after that blast, that whole
area looked like hell on earth.

YATES-ORR: Images of
the explosion show

that this happened in
an industrial area.

NARRATOR: Could the
fiery vortex in Redding

been produced by an explosion?

- But where would
the explosives come from?

- In the suburbs, it's not likely
that you're gonna have

huge amounts of flammable
or explosive materials.

KOUROUNIS: I doubt this fire is the
result of some kind of an explosion.

- So what could be causing
this massive fire?

NARRATOR: Perhaps the answer lies
in the enormous columns of smoke.

- The shape kinda reminds me of
the huge columns of ash

you see from erupting volcanoes.

YATES-ORR: There are 20 volcanoes
in California,

and seven of them are likely
to erupt again.

NARRATOR: The most recent
eruption was less than

75 kilometres from Redding.

- The last substantial eruption in
California was Mount Lassen,

and that was all the way
back in May 1915.

That was a disaster.

KOUROUNIS: Over four days, the
volcano spews molten lava and rock,

destroying everything in its path.

- The effects of
Mount Lassen's eruption

were felt for hundreds of miles,
including in Redding.

NARRATOR: Geologists still believe
the chances of another eruption

at Mount Lassen are high.

Could the volcano be the source of
Redding's mysterious vortex of fire?

- If we compare volcanic ash columns
to the giant plumes of smoke

seen in Redding,
they may seem similar.

But when you take a closer look,
it doesn't look like ash

filtering in from a nearby volcano.

NARRATOR: And the view from above
reveals the vortex of fire's path

is coming from the opposite
direction of Mount Lassen.

- So, what could be causing
this massive fire?

- When you look closely
at the footage,

you can't help but notice
this extraordinary thing.

It seems there's a rotation
in the flames.

- I've seen spinning activity
like this many times.

It reminds me of the rotation
you'd see in tornadoes,

waterspouts, and even dust devils.

- California definitely has the
right conditions

to produce dust devils.
So, could this fire be the result

of two converging phenomena,
a dust devil and a fire?

KOUROUNIS: Dust devils are vortices
that form when rising pockets of air

above a hot and dry ground create
an updraft that begins to rotate.

NARRATOR: And devils like these
aren't always made of dust.

- Back in 2019, a huge "coal devil"
was captured on video

at a coal mine in Elkhorn,
West Virginia.

KOUROUNIS: The vortex acts
as a low-pressure centre,

drawing in warm air,

including debris like dust,
coal, or even hay,

and then spitting it up and out.

- While they rarely
do any real damage,

the winds in these devils can reach
more than 100 kilometres an hour

and they could be 300 metres tall.
That's like 1,000 feet!

- A thousand-foot-tall spinning
cloud of anything

is not my idea of a good time.

- But none of these so-called devils
contained any fire within it,

which is what we see
in the Redding disaster.

So, could this be the result
of something else?

NARRATOR: Perhaps there's a clue
on the other side of the country,

in Lexington, Kentucky,
where a bourbon distillery

faces a sudden disaster of its own,
a lightning strike.

- In July of 2019,
thunderstorms hit Lexington.

And in the middle of the night,
the nightmare began.

- Nine million litres of bourbon
spilled out onto a retaining pond

and that mixture of fire, water,
and alcohol on the surface,

created what's called a fire whirl.

- Nine million litres of bourbon
going up in flames.

Now, I call that a tragedy
beyond words.

NARRATOR: A fire whirl
is a lot like a "devil",

but the fire creates
its own whirlwind,

spawning flaming vortices.

- A fire whirl can grow
much taller than a devil,

up to 3,000 feet in height.

- That's monstrous!

NARRATOR: Does this explain what the
fiery vortex in Redding really is?

- It's all about the height.

The Empire State building
is over 1,450 feet high.

What we're seeing in Redding
is way taller than that,

almost 18,000 feet!

That is the equivalent of almost 12
and a half Empire State Buildings!

- Way too tall to just
be a fire whirl.

NARRATOR: So, what strange forces
can be conjuring

this gigantic twisting pillar
of smoke and flame?

- In terms of its
size and its rotation,

what it most resembles,
of course, is a tornado.

But what I know about tornadoes
is that they're not usually flaming.

KOUROUNIS: A tornado starts up in
the atmosphere where a violent storm

forms a condensation funnel
made of water, dust, and debris.

Winds can move
up to 250 miles per hour

and these monstrous storms
can tower at 80,000 feet.

Whereas, a fire whirl
begins on the ground

when a whirl of wind combines
with a fire and moves up.

NARRATOR: Perhaps the answer
can't be found from above,

but rather,
with a closer look from within?

RALEY: I was helping
evacuate two subdivisions.

I'd say 40% of the homes
were on fire.

It was very windy.
It was dark, very smoky.

Visibility was terrible.

I could barely see ten feet
in front of my truck.

My vehicle started to get
struck with debris

and it was shaking pretty violently.

It was pushed off the road
and all the windows blew out.

That's when I felt like
something was different.

I've been firefighting for 28 years,

and I had absolutely no idea
what was happening.

NARRATOR: What was it that stunned
the desperate firefighters

in Redding?

- It's possible that a fire whirl
could grow so tall

that it's able to reach into
the clouds and create a storm.

What we could be looking at...

is a firenado.

NARRATOR: Over 12,000 kilometres
away, in Canberra, Australia,

an eerily similar swirling cloud
of smoke and fire

is filmed in 2003.

KOUROUNIS: It started out
as a blazing brush fire

that developed
a windstorm within it.

The Canberra fire whirl got so big,

it generated a convective system

that moved up into the clouds
and produced tornado-like winds

at 250 kilometres an hour.

It was called a fire tornado,
or a firenado.

- (dramatic music)

NARRATOR: Like a tornado,
the phenomenon in Canberra

ripped apart the landscape, but it
also burned everything in its path.

- The destruction was unparalleled,

and it was the only firenado
ever recorded.

- Could this be what we're seeing
in Redding, California?

KOUROUNIS: In Redding,
buildings were demolished

and trees were uprooted.

RALEY: All the bark
was stripped off of the trees,

in a specific path,

all the gravel on the shoulder
of the roads was stripped.

Large power poles were sheared off.

It was a terrifying moment for sure.

Winds inside the burning funnel
were estimated to be

more than 230 kilometres per hour,

making it equivalent to
an EF3 tornado.

NARRATOR: And that
can mean only one thing...

What we're looking at here
in Redding is a firenado.

- The firenado put it on
everybody's radar

that these things are
very possible and they're real.

It was an eye-opener for everybody.

- It's hard to imagine combining
two of the world's most destructive

natural disasters into one event,

but this actually happens.

A raging forest fire can actually
spawn and create a tornado of fire.

NARRATOR: The fire in Redding
was finally contained

at the end of August 2018,
five weeks after it started.

230 acres were destroyed,

costing $1,600 billion in damages.

- A firenado is very powerful,
and very destructive.

I probably won't see anything
like that, ever again.

At least I hope I don't.

NARRATOR: But the Redding fire
would not be the last.

In 2020 alone, there were
three wildfire firenadoes,

and there may be more to come.

- Since the Earth's temperatures
are increasing, so will the chances

of more firenadoes forming and
wreaking serious havoc.

- So, if you ever find yourself
near a large, out-of-control fire

and it gets extremely windy,
you've got two choices,

excuse yourself quickly

or pull out your camera
and start filming.

But I suggest the former.

NARRATOR: From fiery disasters to
the mysterious forces of the ocean,

sometimes the disaster isn't what
you can see, but what you can't.

Like here, roughly
10,000 kilometres away

in the Mediterranean Sea.

This is Malta's Azure Window

a 28-metre-tall limestone arch
located on the island of Gozo,

- It's absolutely stunning.

NARRATOR: First appearing
in the early 1800s

after the collapse of a sea cave,
this natural formation

has since become a major attraction
for millions of tourists.

- It became almost an emblem
of the Maltese islands.

NARRATOR: But on this day,
it has completely vanished.

- Poof!

BELLINGER: Now you see it.
Now you don't.

- I mean, it looks like
it was just vaporized.

NARRATOR: What could have triggered
this massive arch of rock

to collapse into the waters of
Dwerja Bay?

BELLINGER: How does a giant stone
arch just disappear like that?

And who or what
could be responsible?

- It would have to be really,
pretty powerful,

because the history of Malta has
never been short

of explosive conflict.

NARRATOR: Over the centuries,
the Azure Window

has survived countless disasters.

- Malta's location makes
it a strategically crucial site,

and throughout its history,
huge battles have been fought

for control of the island.

NARRATOR: And few
were more destructive

than during the Second World War,

when Axis Forces attacked
the island nation.

- At the time, Malta was the most
bombed area on the planet.

NARRATOR: Despite these
massive bombardments,

the Azure Window survived.

- If it could survive
the Axis attacks,

what could possibly take it out?

- Whatever happened had
to be powerful enough

to crumple a massive piece of rock

that years of direct
threats did not.

NARRATOR: Perhaps the answer lies

with another nation's beloved symbol
almost 9,000 kilometres away,

in Brazil, where a familiar figure
stands above Rio De Janeiro.

KOUROUNIS: The statue
of Christ the Redeemer

is recognizable around the world.

YATES-ORR: The 30-metre statue has
been standing for almost 100 years.

- And one of the key things
it faces being so high?

Lightning.

It's hit around 3 to 5 times
every year.

- And it's not the only one.

Many other landmarks around
the world are regularly hit

with the blasts from above.

NARRATOR: Could a lightning
strike be behind

the sudden disappearance
of the Azure Window?

KOUROUNIS: Malta is a country
with a consistently hot climate,

so thunderstorms are
a regular occurrence.

The main island of Gozo
was once walloped

with over 200 lightning strikes
in one day.

NARRATOR: A closer look at the
images of the Azure Window,

reveals another clue.

GUY: Looking closer at the rock,

I can see what would appear
to be a large crack.

Could that be a mark left
by a lightning strike?

- When a lightning bolt strikes
rock, it can sometimes leave behind

strange formations
known as fulgurites,

glassy scars that look like tubes.

NARRATOR: There doesn't appear to be
any evidence

of fulgurites in the limestone rock.

So, a lightning strike is clearly
not responsible.

- What else can cause this kind
of colossal destruction

in such a localized place?

- It's like something fell from
the sky and smashed it to pieces.

Could the Azure Window have been
taken out by a meteorite?

- It wouldn't be the first time.

One of the oldest rogue
meteorites on record

was the Peekskill meteorite that
crashed into a parked car in 1992.

- Every year in Malta, the Perseid
meteor shower hits Dwerja,

known locally as
the Tears of Saint Lawrence.

GUY: But the Perseid meteor shower
happens in August

and the Azure Window
was destroyed in March.

NARRATOR: Meteorites fall
throughout the year.

In fact, some 17,000
hit Earth annually.

Could one of these have levelled
the Azure Window?

YATES-ORR: In the meteor
calendar for Malta

there was no known meteor activity
in Dwerja Bay on March 8, 2017.

NARRATOR: So, if not from above,

is it possible that disaster
struck from below?

- Just after 8:30am on the day of
the Azure Window's disappearance,

a seismic signal
was recorded... on Gozo.

- Does that mean that
a sudden earthquake

is behind the disappearance?

NARRATOR: 8,000 kilometres away
in Puerto Rico,

a 2020 earthquake
may provide a hint.

- On January 6, 2020, a 5.8
magnitude quake hit,

with an epicentre only 6 kilometres
away from the island.

NARRATOR: And here, another
natural landmark took a major hit.

- Puerto Rico is home
to a rock formation

similar to the Azure Window,

known as Punta Ventana,
or "Window Point".

- You'd think something like this
would be around forever,

but the quake was too much
for it to handle.

NARRATOR: Just like
the Azure Window,

Punta Ventana vanished.

So, could an earthquake
be the culprit on Gozo?

- Malta isn't an
earthquake hotspot,

but it's still very susceptible
to large quakes.

The earliest recorded earthquake
happened in 1693

with an estimated magnitude of 7.4.

NARRATOR: That quake struck Sicily,

170 kilometres away from
the Azure Window.

- There are records of landslides
and building collapse

from the shockwaves that hit Malta.

- And in more recent times,
a magnitude 3.0 earthquake

hit 120 kilometres off
the coast of Malta.

YATES-ORR: The Azure Window
withstood those quakes,

but could another be behind
its disappearance?

NARRATOR: A seismic signal recorded
the day the arch disappeared

reveals another clue.

- That signal had a magnitude
of approximately 1.5.

- That's not a very big quake.

- That's what we call
a microearthquake,

you'd barely feel it.

It doesn't seem possible
that something so small

could take out a massive
rock formation.

NARRATOR: What else could be
behind the disappearance

of the Azure Window?

Perhaps another view from
above can reveal other clues.

GUY: About 90 metres away from
where the Azure Window was

is the blue hole.

A sinkhole measuring 10 metres wide.

NARRATOR: And it's not the only one.

RISKIN: When you take a wider
view of the area,

you notice another nearby sinkhole,

a huge lagoon known
as the Inland Sea.

CARUANA: When you look
at it from the air,

it has this almost perfectly
circular shape

that is really quite striking.

You can't appreciate it the same way

when you look at it from the ground.

NARRATOR: Could a sinkhole
be the cause

of the Azure Window's disappearance?

GUY: A sinkhole is
the result of erosion.

Water seeps into the bedrock
and dissolves it,

creating these cavities
and caves which cause collapse

from the surface above.

RISKIN: They can be big enough to
draw in a vehicle

or even swallow
huge sections of forest.

- Sinkholes can also happen
underwater.

It's plausible that an underwater
sinkhole opened up

and the Azure Window was sucked in.

- I mean, this sounds like
an underwater black hole.

NARRATOR: Has the Azure Window
collapsed into a hidden sinkhole

in the seabed?

A closer view from above reveals

the base of the pillar
is still quite visible,

lying just beneath the ocean waves.

With the remains of the arch
so close to the surface,

a hidden sinkhole is clearly not
the source of the collapse.

So, what did lead to the demise
of this famed Maltese icon?

To solve the mystery, we must
investigate the view from above,

below.

- The initial idea was to gather
a little bit of an understanding

of what had happened
to try and make sense

of the collapse event itself.

NARRATOR: Is it possible the secret
to solving this mystery

lies just beneath
the ocean's surface?

- It was breathtakingly beautiful,

the rock was still quite fresh, so
it was almost shining underwater

with this really bright
white colour.

The base of the pillar
had collapsed,

but for the most part,
it was still there.

It was really quite eroded towards
the top close to the surface.

You could see that it was tapered.

NARRATOR: To discover what happened
here, Dr Caruana's team

employs a technology
known as photogrammetry.

WOOD: The process involves taking
many, many photographs,

which overlap one across
the other to create the 3D model.

- It was quite a challenge to do

because the site
is really quite large.

But over the months and years,
we managed to do just that.

NARRATOR: And the 3D model
reveals a crucial clue.

WOOD: The base of the column
was suffering

from some rather serious erosion.

This was demonstrated very, very
clearly through the 3D model.

You could see the tapering
of the base of the arch

until it reached the surface.
It was maybe, at the surface,

not more than a couple
of metres wide, if that.

NARRATOR: The model also reveals
how the arch met its demise.

- The collapse took
a matter of seconds.

The bridge of the arch collapsed
vertically downwards

upon losing support from the pillar.

The bridge just fell right where
it was,

vertically downwards,

and it's now dispersed
underneath the cliff.

- It's the inevitable process
of nature.

It's the constant pounding of the
north-westerly winds and seas,

which can be very, very violent
on this part of the island.

- On the day of the collapse, there
were reports of high winds

around Gozo.

NARRATOR: Wind speeds over
70 kilometres per hour,

and waves 3 metres high
were reported.

This battering of wind and sea
coupled with a weakened structure

lead to the arch's collapse.

- The Azure Window wasn't
destroyed by a literal storm,

but it was destroyed by a perfect
storm of unfortunate circumstances.

- In other words, it collapsed
because of a combination of wind,

waves, and erosion.

NARRATOR: But what about the
mysterious earthquake signal?

- The timing is so close to the
Azure Window's disappearance,

it makes a lot of sense to think
they've got to be connected.

NARRATOR: And they are.

In 2018, researchers proved
that the signal was indeed

the result of the Azure Window
hitting the sea floor.

YATES-ORR: That signal was the voice
of the Azure Window as it fell.

NARRATOR: After falling prey to
decades of erosion,

what does the future hold
for the Azure Window?

BELLINGER: An iconic feature,
beloved above the waters,

will soon take on
a new purpose below.

- As a reef, the Azure Window
will become an important feature

in sustaining the underwater life
in Dwerja Bay.

- It'll also become a different
type of attraction

for a different type of tourist.

CARUANA: Every time I dive
the Azure Window remains,

I'm left in awe at the beauty

that nature can craft as
it continues to mould the landscape.

It is a continuous process.

It has found new life under the sea.

NARRATOR: While some disasters
hide beneath the waves,

others are unseen and present
unthinkable dangers.

Chernobyl, Ukraine,

the site of the world's most
infamous man-made disaster.

- The explosion was the largest
uncontrolled radioactive release

into the environment ever recorded.

- To this day, it is the world's
worst nuclear disaster.

NARRATOR: Now, more than
35 years after the catastrophe,

the reactor is in ruins, and
the surrounding land, abandoned.

- I have been to Chernobyl
and it is hands down

the creepiest place that
I have ever experienced.

Everywhere you look, the buildings
are crumbling and decaying.

NARRATOR: And now, startling new
research from above

reveals a lethal threat.

A drone measuring radiation
around the site

discovers something frightening.
- What is that?

- We were able to detect
a very highly localized

and intensely radioactive area.

- Finding a spike like this decades
after the explosion is alarming.

NARRATOR: And even more
unsettling, its location.

An abandoned village called Kopachi.

- Kopachi wasn't an area where we
were expecting to see anything.

You would think all
the high levels of radiation

would be close to the reactor.

- I wanna know, why is there
radioactivity right there?

- Could this radioactive
hotspot in Kopachi

be a contaminated fragment thrown
from the original explosion?

NARRATOR: Perhaps we can find
a clue 6,500 kilometres away

and over 100 years in the past.

- Before the nuclear age, human
beings were still perfectly capable

of causing sudden mass destruction.

And one of the biggest disasters
was in Halifax, Nova Scotia.

HOFFMAN: During the First World War,
a munitions ship

carrying almost 3,000 tonnes
of explosives,

collided with another
in the harbour.

The resulting blast was the largest
human-made explosion

up until that time.

- It was the equivalent
of about 3 kilotons of TNT.

The shockwave was just huge,

it shattered windows up
to 100 kilometres away,

and the anchor from
the exploding ship

actually flew 4 kilometres
before it hit the ground.

NARRATOR: Is it possible a piece of
debris from the Chernobyl explosion

is the source of the mysterious
radioactive hotpot near Kopachi?

- The explosion
was incredibly powerful.

I mean, it was like nothing
the world had ever seen before.

- It was a moment that
changed history.

NARRATOR: On April 26th, 1986,

two massive explosions blasted
the 1000-tonne roof

off nuclear reactor number 4.

- The explosion blew radioactive
fuel particles into the air

in every direction, and then
caused a massive fire

of radioactive materials
at the site.

NARRATOR: But was the explosion big
enough to be the source

of the mysterious radioactivity.

- Given that Kopachi is more than
4 kilometres from the epicentre

of Chernobyl, it's pretty unlikely
that the hotspot we are seeing

comes from that explosion.

- But it could be possible.

Because that's almost as far
the Halifax explosion

threw that massive anchor.

What we need is more information.

NARRATOR: Another view
from above reveals another clue,

a former secret Soviet installation
just south of Kopachi.

- What we know is at the time of the
explosion, the Chernobyl area

was actually the site of
two military installations.

NARRATOR: One of these was a missile
defence station,

the other, a secret military base.

According to one news report,
at least three rockets

armed with nuclear warheads
were present.

But after the Chernobyl explosion,
they had to be moved... and quickly.

HOFFMAN: We know from previously
classified Soviet records

that dozens of missiles were
quickly loaded onto trucks.

- Could it be possible that during
the chaos after the explosion,

some of the nuclear warheads
were moved to Kopachi?

NARRATOR: And if so, why would
the Russians hide them there?

- Perhaps it's not the Soviets
hiding nukes in Kopachi.

NARRATOR: When the
Soviet Union fell in 1991,

just 5 years after the Chernobyl
disaster, it left Ukraine

with the world's third largest
arsenal of nuclear weapons.

It's believed they
surrendered all of these

in return for security
from the west.

- But did the Ukrainians
return everything?

Could they have kept some
weapons-grade materials

for themselves?

- This might explain why the
Russians have showed this,

kind of, bizarre interest in
Chernobyl when they invaded Ukraine.

NARRATOR: In the spring of 2022,

Chernobyl was occupied by the
Russians, and no one knows why.

- Russian soldiers have been seen
digging trenches there.

It's hard to understand why they
would want to gain access

to an abandoned nuclear power plant.

Why would the soldiers take
such a daunting risk?

- One possibility is that they're
searching for hidden

and highly valuable
radioactive material.

NARRATOR: What nuclear secrets were
the Russian soldiers hoping to find?

- Plutonium is the primary element
used to produce nuclear weapons.

Is it possible that
this valuable resource

can still be found at Chernobyl?

- The possibility that somebody
could be making bombs from this

is really frightening.

- Now if that were true,
that of course,

could lead to a third World War.

NARRATOR: Could this
really be the source

of the radioactive readings
near Kopachi?

- Whatever it is, its obviously
not supposed to be there.

NARRATOR: So, how did it get there,
and what is it?

- Could this hotspot be
the indication

of leftover weapons-grade
plutonium?

- An RBMK reactor such as Chernobyl

is primarily for breeding
weapons plutonium.

NARRATOR: Is this why the Russians
occupied Chernobyl

in the early days of
their invasion of Ukraine?

- If someone's trying to create
bombs from plutonium,

the world needs
to be paying attention.

- The first nuclear bombs were
dropped in 1945 in Japan,

killing tens of thousands of people
and devastating two entire cities.

It's the only time that nuclear
weapons have been used in warfare,

and hopefully the last.

NARRATOR: After a thorough scan over
the entire area

surrounding the hotspot,

results from the research
drone are encouraging.

There are no signs of plutonium.

- That's a relief.
But we still don't know

what the Russians
wanted with Chernobyl.

NARRATOR: Could it simply be
a question of location?

- Chernobyl sits right on the
shortest route

between Belarus and Kiev.

That, of course,
is Ukraine's capital.

Now, that makes a potentially
useful line of attack

for invading Russian forces.

NARRATOR: Their presence at
Chernobyl

may have nothing to do
with nuclear materials,

but what does that mean
for the hotspot?

- Since there's no rogue
plutonium in Kopachi,

what else is there that could create
so much radiation

35 years after the explosion
was cleaned up?

NARRATOR: Maybe the second worst
nuclear disaster in history

can offer a clue?

Almost 8,000 kilometres away,
in Fukushima, Japan.

WALTERS: In 2011, there was
this massive tsunami

which completely overwhelmed the
Fukushima Nuclear Power Plant,

and that caused three
nuclear meltdowns,

three hydrogen explosions,

and as a result, it released
a huge amount of radiation.

- A 20-kilometre radius around
the site was evacuated,

but some people had to remain
in and around the plant

to stabilize the disaster site.

NARRATOR: To manage
radioactive debris,

remote control machinery
was used to find

and store the deadly material.

- Over $150 billion has been spent
on the containment efforts

at Fukushima, and there's
hope that that site

will be completely decontaminated
by the year 2050.

- Chernobyl, frankly,
was not so lucky.

You know, scientists say that it's
gonna take at least 20,000 years

before the site becomes
habitable again.

- And that's partly because the
cleanup at Chernobyl

was not nearly as organized
as Fukushima.

KOUROUNIS: The immediate aftermath
of the Chernobyl explosion

was a time of intense
chaos and fear.

The cleanup has been massive, but
it was not entirely well-managed,

given the emergency circumstances.

- Evacuations weren't immediately
ordered,

and so thousands of people
unknowingly went about their days

while being exposed to really
dangerous levels of radiation.

NARRATOR: When evacuation
orders finally went out,

panic set in.

- People left so fast, you can still
see items sitting

where they were dropped haphazardly
over three decades ago.

GUY: It looks like time
just stopped.

NARRATOR: With the residents fleeing
to safety,

the deadly site of the disaster had
to be fought with full force.

WALTERS: After the explosion,
you have thousands of people,

who risked their lives working as
what was known as "liquidators".

And their job was to clean up
all those deadly materials.

The most disturbing thing for me
about the Chernobyl disaster

wasn't just the kind of reckless
managerial incompetence

that led to it.

It was the bravery of those
who had to clean it up,

who knew that this was going
to lead to their deaths.

MARTIN: Due to the magnitude of the
accident and the haste in which

the liquidation activities
were performed,

no actual records
were able to be kept.

There are so many unknowns.

- Given that the Chernobyl cleanup
was such a mess,

could this hotspot be the result of
a long-forgotten pile

of radioactive waste?

NARRATOR: To solve the mystery,
researchers have little choice

but to continue their
investigation... on the ground.

- We couldn't just leave it.
We had to go in as scientists

to work out what was causing
this kind of anomaly to exist.

- For me, studying and collecting
the radioactive data

from the distance of a flying
drone is good enough.

NARRATOR: Soon, the team makes
a dangerous discovery.

MARTIN: Our personal dosimeters
started to go off.

The beeping starts,
everything starts flashing.

- I'm not so sure how much
farther I'd walk

once all the radiation
alarms go off.

- It was only then we actually
realized,

"Ah, this is the radioactive hotspot
that we had seen from above."

NARRATOR: So what deadly force
continues to lurk

in this forbidden landscape?

- We saw this kind of
bowl-shaped depression

and some large metal structures

inside three large, metallic,
iron hoppers.

As you then get
progressively closer,

your dosimeter starting to flash
red, everything started to beep.

Your Giger counter starting to find
radiation that are too high

for it to actually measure.

And that's when we actually
found this hotspot.

NARRATOR: What are these
strange metal structures,

and why are they
giving off so much radiation?

- Kopachi was a small farming
village outside of Chernobyl.

These metal hoppers would normally
have been used to bag animal feed,

but were most likely sequestered
by the liquidators

for their radioactive dirty work.

NARRATOR: Readings indicate
that it's nuclear fuel waste,

radioactive material left
accidentally in the hoppers

for over 35 years.

The discovery solves
the mystery of the hotspot,

but the researchers still have
more ground to cover.

- This site of nuclear material
was formerly unknown

to almost all of the authorities
within the zone.

Hence, there is now an even more
pressing need to get back out there.

- Mapping the Chernobyl site is
important,

because with this information,

local authorities can accurately
isolate these dangerous no-go zones,

making the area safer
for future researchers,

tourists, and even redevelopment.

NARRATOR: Experts may have deemed
the exclusion zone unliveable

for 20,000 years, but it could have
a surprisingly "clean" future.

- By utilizing the areas
already-built power network,

Ukrainian officials
are considering the construction

of solar energy farms on
the least radioactive areas

of the exclusion zone.

- So, because of the deadly
environmental disaster at Chernobyl,

a newer and cleaner energy source

may find itself
a permanent home there.

- Here's hoping.

NARRATOR: From a barren
man-made disaster zone

to pristine alpine slopes,

some catastrophes seem
to come out of the blue.

In the Italian alps, nestled
beside the Dolomites,

lies the idyllic Lake Carezza.

- Crystal clear waters,
stunning mountain views.

I mean, this place is
absolutely gorgeous.

NARRATOR: But in the fall of 2018,

the surrounding woodlands
were transformed

into a disaster beyond
comprehension.

- My God, these trees have
been massacred.

It looks like a crime scene.

- It's like a graveyard of trees.

There's something really
eerie about this place.

- This landscape looks apocalyptic.

NARRATOR: And the view from above
reveals something strange

about the destruction.

- Huge swaths of trees
have been flattened,

but right beside them,
are others completely untouched.

- When you look at the live trees
versus the dead trees,

it almost seems like someone or
something

is choosing what to destroy.

NARRATOR: What powerful force could
be so destructive

and yet so selective?

- Could it be some kind of disease?

I mean, that might explain why
only some sections of trees

have collapsed but not others.

NARRATOR: How did a disease make
its way into this remote forest?

Perhaps there's a clue
in Italy's past.

- Researchers believe that one
possibility reached Italy

by accident in the 1940s.

RISKIN: There's a fungus called
Heterobasidion annosum.

NARRATOR: In the United States,
this tree killer

causes $1 billion in damages
every year.

But what is it doing in Italy?

- Genetic analyses showed this
probably came over from the US,

most likely with troops during
the Second World War

hidden within their
wooden equipment.

It spread throughout
coastal Italy since.

Sometimes fungi aren't that fun.

NARRATOR: But these trees
are in the mountains,

far from Italy's coast.

So, what else could be behind
this obliteration?

Over 8,000 kilometres away, another
tree killer could provide a clue.

- For decades,
one tiny little creature

has been devastating the forests
of the American West.

RISKIN: Bark beetles. Since 2005,

they've destroyed
millions of acres of forest.

- We're talking up to
100,000 trees a day

getting taken out
by these little insects.

They're really small, but they can
cause seriously big problems.

- Talk about
an ecological nightmare.

- And it could be getting
a lot worse.

- Climate change has led to
an increase in the populations

of bark beetles,
so it's indirectly responsible

for what many people call
the biggest insect outbreak

in the history of the planet.

- Could a tiny insect be responsible
for a disaster of this size?

NARRATOR: A closer look from above
reveals that this is unlikely.

- These trees look like they were
healthy before they were flattened.

KOUROUNIS: There's no evidence
of insect infestation.

So what's going on here?

- What on earth
could have done this?

NARRATOR: Perhaps
the answer is not on earth,

but rather, in the skies?

- When you look closely, there
appears to be

some kind of smoky haze in the air.

NARRATOR: What is this mystery mist?

A few hundred kilometres away,
in another part of northern Italy,

there may be a clue.

HOFFMAN: In 2017,
the town of Turin, Italy,

suffered an enormous fire that
burned over 1600 hectares of forest.

- That's over 3,000 football fields.

The smoke from the fire lingered
in the air for weeks

as the fire burned itself out.

- Could this be the source of all
that destruction at Lake Carezza?

Is it possible that this could
simply be the aftermath

of a raging forest fire?

- You know what they say?
When there's smoke, there's fire.

- But it doesn't look
like a forest fire.

When you look at it from above,
it doesn't show any individual trees

that are burnt or burning.

GUY: Whatever is creating
that smoky substance,

it's not the trees themselves.

NARRATOR: So what is creating
the haze above the forest?

- There have been rare circumstances
in the past where smoke exists

without any evidence of fire,
at least not any fire above ground.

NARRATOR: Could the secret to
solving this mystery

lay buried deep below
the Earth's surface?

Perhaps the key to solving
this mystery is not from above

but below.

A disaster from the past,
almost 7,000 kilometres away,

could hint at the answer.

HOFFMAN: In 1962, the town of
Centralia, Pennsylvania,

tried to clean up a landfill
by setting fire to it.

It didn't go exactly as planned.

The fire was not properly
extinguished,

and it travelled into the unsealed
opening of a strip mine.

NARRATOR: Centralia once
boasted 14 active coal mines,

interconnected by
a labyrinth of tunnels.

- At the time of the fire, people
thought the blaze

would burn out quickly, but it
spread to all of Centralia's mines.

All the trees in the town died.

The ground turned to ash

and people left for fear
of carbon monoxide poisoning.

HOFFMAN: Now, Centralia
is almost a ghost town.

NARRATOR: 15 square kilometres in
size, and at points, 90 metres deep,

the fire proved impossible
to put out.

GUY: Six decades later,
the fires are still burning.

- And experts believe that
the coal supply there is so large

that it could take another
250 years for it to burn out.

But is that what is happening
around Lake Carezza?

- Unlike Pennsylvania,
the smoke near Carezza

is not escaping from exit points
in the ground.

KOUROUNIS: And looking closer
at the smoky haze,

the way it's hanging in the air,
makes me question something.

Carezza is a mountainous region,
and the weather can change rapidly.

The haze is most likely not smoke,
but mountain fog.

Obviously, fog can't do damage
to mountain forests,

so what other options do we have?

- When I think of other disasters
in the mountains,

I think of violent acts of nature,
avalanches, landslides.

- Mountain landslides can cause
a massive death and destruction.

NARRATOR: Disasters like landslide
8,500 kilometres away

hit rural Washington.

- In 2014, the Oso landslide in
Washington State

propelled mud and debris
over 2.6 kilometres.

- This disaster came thanks to
a deadly combination

of unstable land and a massive
amount of rain.

KOUROUNIS: An estimated 10 million
cubic metres of material

turned into a tsunami of mud.

In some places, the slide
was over 21 metres deep.

- The sudden slide hit an
unsuspecting neighbourhood below,

killing 43 people.

- A landslide could explain why
some trees have fallen

while other ones haven't,

and there's evidence of soil
and rocks around the broken trees.

NARRATOR: But the mountains around
Lake Carezza show no sign

of a typical landslide carnage,

so what other forces
could be at play?

- Perhaps the pattern
of destruction,

the way the trees have collapsed,
can offer a clue.

- Seeing so many trees toppled
like this, I can't help but wonder

if a tornado is responsible.

They're certainly capable of
colossal damage like this.

NARRATOR: Tornadoes
are uncommon in Italy,

but one touched down
in Venice in 2015.

And in 2021, 12 twisters
were reported in Sicily.

- Typically, when most people
think of tornadoes,

they think of flat ground,
like Kansas,

but they actually can happen
almost anywhere.

In some cases, mountains may
actually help tornadoes form.

NARRATOR: Just like
in Virginia in 2011,

when two tornadoes formed at
elevation on Draper Mountain.

- You've really gotta wonder how
a tornado could really get moving

with all these big mountains
in the way.

- Some scientists believe that
the change in elevation

due to the storms
crossing the ridge,

may have caused the updraft
to rotate even faster.

It's called vorticity stretching.

- Super tornadoes, is that what
could have happened to Carezza?

That would explain why the trees
look like scattered matchsticks.

NARRATOR: But this destruction
doesn't match

the pattern usually associated
with tornadoes.

KOUROUNIS: Typically, with a
tornado, there's a single funnel

coming from the base of the storm
that travels along one path.

- There's no single path
of destruction here.

What we're seeing is large swaths of
trees torn out in multiple areas.

- It's almost like several tornadoes
descended all at once.

- When I think about it, there is
another extreme weather event

that is a possibility.

We could be looking at
the aftermath of a cyclone.

Unlike a tornado, which is tall
and contains a funnel cloud,

a cyclone is a wider, rapidly
rotating low-pressure storm system.

NARRATOR: A cyclone contains
a spiral of high winds

and multiple storms which carve
numerous paths of devastation.

- This may explain why
the destruction was in

several different sections
in the forest.

- To know for sure, we'd need to
see what the weather was like

in and around Carezza
at the time of the disaster.

NARRATOR: In 2018, Cyclone Vaia
struck northeast Italy,

including Lake Carezza.

Wind gusts reaching almost
200 kilometres per hour

and destroyed 8 million
cubic metres of trees.

- That's equivalent to Italy's
entire harvest of wood for a year.

It's incredibly scary that
in almost an instant

so much was lost by an unusual

and incredibly rare
extreme weather event.

- Experts say it's gonna
take 150 years or more

for Lake Carezza's forests
to reach their former glory,

but Italy has vowed to protect them.

NARRATOR: Cyclone Vaia
has altered the face

of this once pristine forest
for decades to come.

- Anything with that kind of power
deserves a mark of respect.

NARRATOR: Tornadoes of fire,
vanishing icons,

infamous nuclear accidents
and killer cyclones.

Sometimes a disaster's
devastating power

can only truly be
revealed by a view from above.

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