All language subtitles for Historys.Most.Shocking.S01E04.1080p.WEB.h264-EDITH_track3_[eng]

- Tonight on "History's
Most Shocking,"

an airborne emergency
caught on camera.

- [Tony] Was it an
accident or an acting job?

- If I was in a life
or death situation,

I would not be using
a selfie stick.

- [Tony] Buying this house
was a big mis-snake.

- Reticulated pythons
have something called

indeterminate growth.

- [Tony] Think your
commute is tough?

Try getting to work like this.

- This really looks
like a Hollywood stunt

that's gone horribly wrong.

- [Tony] And before you ride
a bike into a train tunnel,

please, watch this first.

- The first rule
of train tunnels

is to not go into train tunnels.

[train horn blaring]

[dramatic music]

- [Tony] Disasters.

[explosion booming]
- Oh, the humanity.

- [Tony] Shocking video,

life or death decisions,

behind history's caught
on camera moments.

- What to do with
one dead whale.

- [Tony] Are the mysteries
of how and why they happen.

- Some sort of metal fatigue
was most likely at fault.

- It's like a bulldozer.

Very few buildings
can actually withstand

that force of moving water.

- I'm Tony Harris.

[mountain lion roaring]

[engine revving]

Prepare to be shocked.

[dramatic music]

Good evening and welcome to
"History's Most Shocking."

Imagine you are in a plane
and the engine fails.

You might see your whole life
flash in front of your eyes,

or you might see an opportunity.

What do I mean? Check this out.

[tense music]

It's November 24th, 2021,
in Lompoc, California.

Amateur pilot Trevor Jacob

takes off in his 1940
Taylorcraft airplane

for the 220 mile
flight to Mammoth Lakes

to spread the ashes
of a deceased friend

who died in a base
jumping accident.

I just put as many cameras
as I could on the plane

for that specific flight.

I just wanted to make sure
that every angle was covered.

- [Tony] But then, while
cruising at around 8,000 feet,

the plane's engine
suddenly fails.

- [Tony] Trevor
makes the decision

to abandon the powerless plane.

- That specific plane actually
doesn't have a starter,

so you would have to physically
be outside of the aircraft

to prop start the plane.

So I just decided to jump out.

- [Tony] Trevor
films his free fall,

as the unpiloted plane

films its own crash
into the mountains.

[debris crashing]

Meanwhile, he steers his
parachute towards the wreckage,

landing in scrub brush.

[brush rustling]
- (bleep), (bleep).

Oh, get me out of this.

Ow.

Oh my gosh.

- [Tony] Trevor retrieves
his cameras from the plane,

but with the no cell service,

he's forced to hike for
10 hours to find help.

- [Trevor] It felt
like a hundred degrees.

I'm crawling through poison
oak, getting all cut up.

Ow.

- [Tony] Well after nightfall,

Trevor is finally
rescued by local farmers.

- [Trevor] Hello.

- Oh my gosh.

That was the gnarliest
day of my life.

I was completely drained.

I was just like, literally
just so happy to be alive.

- [Tony] Trevor's
fateful plane ride

racked up more than 4
million hits online,

but soon, astute viewers

started seeing strange
inconsistencies,

and began to question whether

or not this was
a true emergency.

Did the popular YouTuber
survive a real crash?

Or was it all a stunt?

Let's see how our experts
navigate this one.

[tense music]

On the one hand, small plane
crashes aren't that uncommon,

and data from 2019

showed the rate of
private plane accidents

was 25 times higher than the
rate for commercial planes.

This is largely due to
differing levels of experience,

less regulatory oversight,

and fewer requirements
for general aviation.

But despite the evident dangers,

many viewers of this video
began to suspect a trick.

- One of the things a lot of
people pointed out right away

is that as soon as
the engine stops,

he doesn't hesitate,
he just jumps.

But small planes like this
are great for gliding,

and pilots are trained to glide

until they're able
to find a safe place

to put the plane down.

- Normal procedure for a pilot

that is experienced
in engine failure

would be to pitch the
nose of the aircraft down

to increase the
speed of the aircraft

to reach glide speed.

You're maintaining
stable flight,

start looking for
places to land.

We don't see any of
those in this video.

In fact, he appears to be
pulling back on the yoke

and slowing the aircraft down.

- [Tony] And there are
other clues in the video

that don't add up,
like his open door.

- One of the items
on your checklist

before you take off
is, secure the door.

This guy's flying around with
his door already cracked, why?

Big red flag.

- [Tony] Jeff Wise also notes

that despite his
life being in danger,

Trevor appears to have a
bigger priority on his mind.

- When you find yourself in
a life or death situation,

you have an effect that's
called cognitive tunneling,

which means that you aren't able

to think about all the different
things that are going on,

and yet he's carrying
a selfie stick,

which is the most unnecessary
thing you could have

in a life or death situation.

- [Tony] Another thing
might make you go, "Hmm."

Trevor's parachute.

- It's not totally
uncommon for pilots,

particularly in these
small personal aircraft

to have parachutes on board.

Oftentimes these are
emergency chutes,

handy where the
pilot can get to 'em.

What this guy's wearing is a
very different contraption.

It's a sport chute.

It's worn by people
who go up into a plane

with the specific
purpose of jumping out.

- [Tony] The evidence doesn't
add up for authorities either,

especially since Trevor had
the plane wreckage removed

and scrapped before
they could investigate.

Facing criminal prosecution,

Trevor pleaded guilty to
one count of destruction

and concealment,

with the intent to obstruct
a federal investigation.

- I'm not proud of what I did

and I knew in my heart that
that wasn't a good thing to do

and I shouldn't have done that.

I'm grateful that
nobody got hurt.

Oh my gosh.

- The takeaway?
Straight up clickbait.

Trevor intentionally
abandoned his plane

just to film the crash.

Despite Trevor's contrition,

he was sentenced to six
months in federal prison.

Oh, and remember
his buddy's ashes?

Well, exploiting human remains

for a publicity stunt isn't a
crime, but maybe it should be.

Moving on.

When most of us call
the exterminator,

it's to control common household
pests like roaches or mice.

Those are certainly stressful,

but imagine if your home was
infested by something bigger,

longer, and much more dangerous.

A warning, some of what
you're about to see

may be disturbing.

[tense music]

February 12th, 2023,
Pahang state, Malaysia.

A family reports hearing
strange creaking sounds

coming from the
attic of their home.

They call in some professionals

who start probing the
ceiling with poles.

Coming out of a
hole in the ceiling

is a long tail,
curling and twitching.

This can't be good.

After a few more prods,
there's a cracking sound

and then...

[ceiling cracking]
[people exclaiming]

The whole ceiling
comes crashing down,

exposing two huge,
intertwined pythons,

measuring more than a
combined 30 feet in length.

In case you need more nightmare
fuel, let's see that again.

[ceiling cracking]
[people exclaiming]

And they aren't only
creepy and crawly.

These animals are some of the
deadliest predators on Earth.

- These snakes are
reticulated pythons,

and wild, reticulated pythons

are said to be
pretty aggressive,

and they are constrictors,

which means they kill by
suffocating their prey,

and they're actually a pretty
big problem in Malaysia

and Indonesia.

Some people have even found
them in their toilet bowls.

- Reticulated pythons

have something called
indeterminate growth,

which really means that
there's no set point

to how big they can get.

These two pythons weighed
together 110 pounds.

It's really like
having a small woman

up there in your ceiling.

- [Tony] These pythons
are known to eat anything

they can unhinge
their jaws around,

including crocodiles like
this unlucky specimen,

and even, occasionally, humans.

In fact, in March of 2017,

not far from where
this video was taken,

an Indonesian farmer went
missing for several days.

And when the locals discovered
a 23 foot long python

with a distended stomach,

they sliced it open,

revealing the unfortunate
man's remains.

- There have even
been reported cases

of these reticulated
pythons eating the children

of hunter-gatherers who
lived in the jungle.

- Think this won't happen to you
because you're in the States?

Think again.

Because of the exotic
pet trade in Florida,

non-native Burmese pythons
have become one of the state's

most concerning
invasive species.

But this video raises questions.

Why were these huge
snakes in the attic?

And is this the right way

to handle that
horrifying situation

if it happens in your house?

[tense music]

[ceiling cracking]
[people exclaiming]

- Snakes are capable
of sniffing out mice

or any sort of food
that's in the house.

So it's very
appealing to a snake

to find a place within your home

that offers them either
the heat that they need

or the coolness that they need,

while also getting
some free food.

- [Tony] Snakes of all types
from around the world,

including here in the US,
rely on stable climates

to regulate their
cold-blooded temperatures.

Since warm air rises in a
home with good ventilation,

this makes your attic
the perfect destination.

There's also a
higher probability

of encountering some
vermin to snack on.

Think about that the next time

you hear a strange
sound up in the ceiling.

Dr. Mayor also suspects
an additional detail

about these snakes

that may have prompted
them to seek shelter.

- The funny part about
the snakes coming down

is that they were
actually mating,

so they interrupted what
could have possibly become

quite a lot more
snakes in that ceiling.

- [Tony] So did this
family make it out alive?

Well, it took an hour, but
the animal control team

finally got the snakes
out of the house.

But what can you do if you
find a snake in your home?

- They definitely
did the right thing

by calling professionals.

These snakes are so
large and strong,

even when professionals
are handling them,

they recommend one person
per meter of the snake

because they're so able to
rapidly coil around you.

So for a regular person
to get these snakes down,

it would've been
life threatening.

- The best thing is to
identify the snake so that

you know what appropriate
actions you can take.

A venomous snake can
be very dangerous.

Snake venom works
incredibly quickly,

and it's especially true with
small pets and small children.

I'm gonna go check my ceiling
when I get home today.

- Our takeaway, these
were mating snakes

looking for a dark
private place.

In this case, the snakes
were released in a safe place

in the wild, but here in
the US, it's another story.

South Florida's python
elimination program,

which began in 2017,

recently captured and
euthanized its 8,000th python

in an effort to rebalance
the Everglades ecosystem.

- We seem to have a fascination
with great white sharks,

and really, can you blame us?

Getting the chance to see one
of these amazing creatures

up close and personal
is a rare opportunity,

but for the cage diving
tourist in our next video,

this great white
encounter was very close

to being his last.

[tense music]

October 2016, a group
of amateur divers

is on a five day shark cruise

off the coast of
Guadalupe Island, Mexico.

The divers are taking
turns submerging

into the water using
specialized protective cages,

while the ship's crew members
bait the water with tuna.

Everything seems to be
going according to plan,

when suddenly, a great
white shark gobbles up

one of the tied tuna shanks

and starts thrashing
about violently.

The frenzied beast
then smashes his way

inside one of the diving cages.

Take a closer look.

We see a shark fin
struggling between the bars.

- [Recorder] Oh my God.

- [Tony] And what appears to be
blood coming to the surface.

Then the shark explodes
upwards in a crimson mist,

flailing about until
it finally escapes.

- [Tony] Actually, that's wrong.

There is someone in the cage,

and that crimson plume of
blood is not a good sign.

How could one man
survive being caged up

with one of the ocean's
deadliest predators?

- [George] They've
got a bite force

of up to 4,000 pounds
per square inch.

- [Tony] For comparison,

the bite force of
the average human

is only 162 pounds
per square inch.

- Their jaws are lined with five

or six rows of continuously
regrowing teeth.

These things are built to kill.

- [Tony] And if you think
the frightening encounter

in this video was a fluke,

Kourounis warns that this
has already happened again

right in the same location.

- Just three years after
this video was taken,

another great white ended
up decapitating itself

after getting snarled up
in one of these cages.

Because of encounters like this,

the Mexican authorities
have really cracked down

and tried to protect
these sharks.

- The idea for shark cage
diving goes back to the 1950s,

although it really didn't
catch on until the mid 1970s

after the release
of the film "Jaws."

But the questions are,
why does this happen?

Is the shark attacking the
cage to get at the diver?

Or is there another explanation?

[tense music]

Critics of these
tourist shark dives

frequently point to the
excessive amount of bloody chum

used to attract these
fearsome creatures.

- Sharks are extremely
large predators

and they can sense blood
from hundreds of yards away,

and we're overtaking its senses
by also chumming the water,

so it's in sensory overload.

This is why we have
a feeding frenzy

or what we perceive as very
aggressive behavior in sharks.

- [Tony] In fact, thanks to
their nostrils being lined

with tons and tons
of sensory cells

called olfactory epithelium,

scientists believe great whites

can detect a single
drop of blood

floating within 10
billion drops of water.

- These shark cages offer
a false sense of security.

While they look safe,

a lot of the times, there
are large enough openings

for a shark to get in,

but then not to really be able
to turn around and get out.

I would rather be in the
water with the shark,

because at that point,
at least I have eyes

on the animal and I have space,

and more importantly,
the shark has space.

- [Tony] Amazingly,
in this video,

you can see the crew
pulls up the diver

who had been in the cage with
the shark the entire time,

and miraculously,
he is unharmed.

That blood was from
wounds the shark received

while smashing through
the steel cage.

Still, Mayor believes
people shouldn't be deterred

from swimming with
great white sharks.

They just need to
do it correctly.

- If you do find yourself
in a situation like this,

the best thing to do

is to try to duck down
as low as possible

and as far away from the
shark as you possibly can,

because the shark's
natural instinct,

and you see it in this video,
is to immediately swim up

and try to get out of the cage.

All it wants to do is
escape, not attack.

- Our takeaway, this is
natural shark behavior.

We agree with our experts

that using chum
to attract sharks

is only going to lead
to more situations

like what we see here.

But because of videos like this,

governments are taking action.

As of early 2023,

all great white cage
diving in Isla Guadalupe

has been banned
until further notice.

Now let's move from the
ocean back to terra firma,

or in this case, terror firma.

Easy question, a freight
train versus a bicycle.

Who's gonna win?

Hard question.

What would you do if
you were on the bike?

[tense music]

May 12th, 2018,
Barra Mansa, Brazil.

Two cyclists are out for a ride.

They brought along
a small camera,

but they forgot to pack
their common sense.

- They're trying to
avoid the main highway,

and their choices to do
that are either swim down

through a river,
climb some rocks,

or go through a train tunnel,

and I think you can see
where this is headed.

- [Tony] The tunnel is dark
and quiet as they enter,

but not for long.

20 seconds in, right
here, is the uh-oh moment,

as they first see the lights

and hear the dreadful
sound of an oncoming train.

- [Tony] Frantic,
the cyclist filming

throws down his bike and
makes a run for the entrance.

Has this hapless pair made
their last wrong turn?

Or is there light at
the end of the tunnel?

Stay with us.

[train horn blaring]

- [Tony] A pair of cyclists has
ventured into a train tunnel.

- [Tony] Much to their regret.

[train horn blaring]

But despite this
remarkable combination

of bad judgment and bad luck...

[train horn blaring]
[intense music]

The two make it out,

with a ferocious locomotive
hot on their tail.

- I went frame by frame,

and it was 60 frames

between the time that
he left the tunnel

and the time the
train left the tunnel.

That equates to two seconds,

only two seconds between
life and death for this guy.

- [Tony] As soon as
the coast is clear,

the cyclist goes
back into the tunnel

and safely retrieves his bike.

But not everyone who trespasses
on train tracks is so lucky.

- Each year in the US,

there are roughly 400 trespass
fatalities on train tracks

and almost as many injuries.

- [Tony] In fact, 94% of
rail related fatalities

in the US take
place at crossings

or as a result of
trespassing, like these guys.

The stats are as
scary as the footage,

but just how close
did these guys come

to getting themselves killed?

Let's break it down.

[tense music]

Surprisingly, running for it

might have been the
most natural response,

but perhaps not the smartest.

- Tunnels are, on the
average, about 15 feet wide.

Railroad cars are about
10 feet, 8 inches wide.

So you're gonna have about
two feet on each side.

Generally you'll
have enough clearance

and space there to
survive a passing train.

- [Tony] And look, the
video provides a major clue

that proves the point.

- When the guy went
back to retrieve it,

the bike was still in good
condition, it hadn't been hit.

So if he had just
laid down prone,

parallel to the
wall of the tunnel,

he would've had
probably plenty of room

to have the train
safely pass over him.

- [Tony] Quimby
asserts that trying

to leave the tunnel was
actually the riskier decision.

- Most people don't
outrun trains.

Even if they can see you,

they generally can't stop
within their sight distance.

- [Tony] A train's speed
limit depends on location

and conditions,

but a train going
just 55 miles per hour

could take up to
a mile and a half

to come to a complete stop,

that's a distance of
about 20 football fields.

- If you want to avoid
completely getting hurt,

don't go in the
tunnel to begin with.

These guys are lucky

that their foolishness
didn't cost 'em their lives.

- The takeaway? Never do this.

Obviously.

If you have to cross
tracks while biking,

cross at a 90 degree
angle and walk,

don't ride across.

That way your wheels
won't get stuck.

When you see an 18
wheeler on the highway,

does your heart skip a beat?

Do you speed up to pass it
or slow down to avoid it?

For many drivers,
sharing the road

with these colossal trucks
is downright nerve-racking.

And as one driver found
out, the fear is justified.

[tense music]

November 30th, 2021.

It's morning on Highway I-294

in the western
outskirts of Chicago.

A dash cam shows an 18
wheeler in the lanes ahead

leaving a trail of smoke behind.

At first, you'd
assume this big rig

definitely needs an oil
change or a new muffler,

but nobody in their wildest
dreams expected to see this.

A car is wedged at a
perpendicular angle

underneath the 18
wheeler's trailer.

And if that wasn't wild enough,

suddenly, 19-year-old Laylisha
Gardner pokes her head out

of the demolished
driver's side window.

- I don't know what's
worse about this footage,

thinking that someone was
seriously hurt or even killed,

or knowing that there's
someone who's awake

and aware enough to wave
around looking for help.

- This looks like a Hollywood
stunt gone horribly wrong.

- [Tony] Meanwhile, another
camera captures the action

from the other
side of the truck.

And while this crazy crash
may seem unprecedented,

there's actually a name
for this kind of accident.

- They're called underrides.

There are federal statistics

that go back as
far as the 1960s,

describing the number
of these incidents

and how often they occur.

- [Tony] In fact, a
famous underride accident

from the 1960s is among one
of the earliest reported.

- In 1967, the actress,
Jayne Mansfield

was riding behind a truck

and the truck slowed to
about 30 miles an hour,

but Mansfield's driver
did not slow down in time

and he slipped right
underneath the truck.

The top half of the car
was absolutely destroyed

and three passengers were
killed, including the actress.

- According to the
National Highway

Traffic Safety Administration,

underride crashes killed
more than 400 people in 2021.

But what accidents like this
to happen in the first place?

And what happened here?

We take that question
to our experts.

[tense music]

The research shows that

underride accidents fall
into two categories.

- The first one
we see frequently

where somebody's coming up
behind a tractor trailer

not paying attention,

and they stuff their car
under the back of a trailer.

- [Tony] The second
is what we see here,

when a car goes
under the trailer

at a perpendicular angle.

- It's usually at
an intersection,

when they're
crisscrossing each other,

or the truck making a U-turn.

But in this case, they
were traveling parallel

and because they were parallel,

it's hard to figure out
how they got there.

- [Tony] According to reports,

Laylisha says she was
just changing lanes.

- It's unclear why she
didn't see the truck,

but you have to always
consider factors like glare

and whether the sun's
a contributing factor,

or whether just the
fact that she was low

and the truck is white.

- [Tony] But the big question

you may have
already been asking,

how come the truck driver
didn't notice the car was there?

News reports indicate Laylisha
was being dragged long enough

to make multiple
phone calls for help.

- Usually, truck drivers
have a convex mirror there

that looks down the side.

The mirrors on the side
and the increased friction,

I'm not sure why the trucker
didn't see her on the side.

- [Tony] Even if
the truck driver

had noticed her right away,

it's a nearly impossible
situation to navigate.

- If I was that truck
driver, what am I gonna do?

I can't pull over necessarily,

'cause that means that
I'm gonna go in an angle,

and the trailer could
go over the car,

and then if people aren't
really paying close attention,

we could have a pile up.

- [Tony] Finally,
motorists are able

to get the truck driver's
attention and he pulls over.

Miraculously,
Laylisha doesn't have

any major physical injuries,

so how did she
make it out alive?

Martinez says she can thank
the aptly named safety cage,

a rigid frame designed
to protect passengers

in the event of a crash.
[car thudding]

- That whole front of
the car disappeared,

but the safety cage was
still pretty much intact.

And that's the only thing
you gotta worry about

if you're trying to
stay alive, right?

It's where your head is,
where your chest is.

- [Tony] But Haight
adds, this type

of underriding accident
is bound to happen again.

While today, rear guards
are mandated on 18 wheelers,

side guards are not.

- The reason for that is
anything you put underneath

the bed of the trailer

minimizes how much ground
clearance you have.

So going over a bump,
going over train tracks,

those sorts of things
become tougher.

- The takeaway, this appears
to be a freak accident

during a lane change.

Despite an apparently
oblivious truck driver,

the accident report
assigned no blame

to either party in the mishap,

but it's likely this won't
be the last time we see this.

Side guards might save lives,

but they still aren't
mandatory in the US.

Mesopotamians
invented the first sewer system

using clay pipes.

Today, modern sewer
systems are ubiquitous,

but have you ever thought about
what's actually down there?

Well, one little
boy in China did,

and he got a pretty
explosive answer.

Check this out.

[tense music]

It's January 22nd,
2021 in Dazhou, China.

A CCTV camera overlooking
a sparsely populated plaza

records a small child
appearing to place something

in the crevice of
a manhole cover

before quickly running away.

Then suddenly...

[explosion booming]

Take another look.

The covers explode off of at
least five manholes arranged

in a diagonal row.

After the explosion,
the police investigated

and discovered the
object the child dropped

was a lit firecracker.

And it's not the first time

something like
this has happened.

- There was actually
an incident in Iran

where a man was standing on
the street smoking a cigarette,

and he decided to toss it
into a hole in the ground

when he was finished,

and that caused the
entire street to explode.

He somehow managed to survive.

He crawled away, his shoes
were blown clean off,

like that's how powerful
the explosion was.

- [Tony] McCarthy says,

these scary situations
really make you stop

to think about what's
flowing beneath our streets.

- There is a whole
world under our feet

that basically transports
things like our water

and our waste and stuff
that we just kind of

toss down the drains,

and it creates kind of a
volatile and mysterious mix.

- [Tony] Among this mix is
a funny sounding substance

known as a fatberg.

- Fatbergs are essentially oils

and fat that have
been turned into soap,

because they undergo this
process called saponification,

where water flowing over
concrete interacts with the fats

and it basically just
makes a giant ball of soap

in the sewer.

They can clog up the
entire sewer system

and cause a lot of damage.

- [Tony] So there's clearly
lots of unsavory stuff

piling up under our cities,

and though what happened in
China may be child's play,

messing with sewers can
be serious business.

[explosion booming]

In 2017, the largest
fatberg ever found

was discovered in
a sewer in London.

The blockage weighed
in at 130 tons,

the equivalent of 11
double decker buses.

But fatbergs aren't
known to explode.

So what happened here?

[tense music]

Our experts say there's a
reason why dropping lit objects

into the ground can cause
huge explosions like this.

[explosion booming]

- Sewers are
particularly dangerous

because they're very
confined, tight spaces

with not a lot of ventilation.

There's a variety of things

that can be
explosive down there,

whether it be methane
gas from human feces

or other bio waste,
industrial waste, gasoline.

So just the littlest spark can
cause an enormous explosion.

- [Tony] Methane is
produced by the breakdown

of organic material
such as human waste.

The pick holes in manhole
covers like these in China

not only help workers open
the covers for access,

they can also ventilate
any buildup of gas.

Yet here we see one
downside to these openings.

They allow entry to things
that shouldn't be there.

So in the US,

there's a lot more
to curbing methane

than just a few pick holes.

- In the United States,

we have different
treatment facilities

throughout our sewer
lines that break down

and remove chemicals.

But these exposed
sewers like in China

and the one in Iran,

don't have to meet the same
standard for treatment.

So the methane is much stronger
and it actually compounds.

- [Tony] So on the surface,

these two explosions
seem very similar,

but there's a wrinkle
with the Iran explosion.

Remember, that one took
out a whole city sidewalk.

It appears that about 15
minutes before the blast,

the same CCTV camera
captured someone

dumping something into the hole.

- That material could have been

gunpowder soaked in gasoline,

but even gunpowder
at its lowest level

when you put a fire to it,
will burn before it explodes.

- [Tony] So Anderson
doubts whatever it was

caused an explosion.

So, what did?

Another theory is a ruptured,

underground natural gas line.

Could that crack be a sign?

Anderson says, "Not so fast."

- A lot of times that gas
ignites and you see a flame.

So you can almost rule out the
idea that it's natural gas.

- [Tony] That leaves only
one possible explanation.

The same culprit as
China, methane gas,

perhaps more concentrated

because of the Iranian
sewer's outdated design.

- I really think
that the one in Iran

was just a sewage canal.

What we have are raw sewage

flowing through the
canals of the street area.

Human methane gas gets
captured in this canal,

and when someone introduces
some type of, form of heat,

it then explodes,

basically like a
pipe bomb going off.

- The takeaway?

Lit objects cause biogas
explosions underground.

Fortunately, explosive sewer gas

is typically prevented
from entering homes

and other buildings,
thanks to plumbing traps

that create a water
seal at points of entry.

Vents also allow dangerous
gases to be exhausted outside.

The Cold War between the West

and the Soviet Union wasn't
just about geopolitics

or the space race, it was also
about the future of aviation,

and a new kind of plane
that many believed

was going to define the future,

until those plans
came crashing down.

[tense music]

June 3rd, 1973,
Goussainville, France.

It's the biannual
Paris Air Show,

and all eyes are on a
revolutionary moment in travel.

Two supersonic passenger planes

that fly more than
two times faster

than the average commercial jet,

reaching speeds above
1,500 miles per hour.

The Concorde, built in a
partnership between Britain

and France,

and the Soviet's Tupolev Tu-144.

- The Soviet's plane
is dubbed by the West

as the Concordski.

It's got the same
delta wing airframe

and downward pointed nose.

Spectators present at the event

were dying to see which
plane would outperform

or outmaneuver the
other in the air.

- [Tony] The Concorde
completes its demonstration

ahead of the Concordski
and without a hitch.

Now it's the Soviet's turn,
but then, disaster strikes.

- [Newscaster] Suddenly,
without warning,

the Concordski is in trouble,
as it goes into a steep climb

and tight turn,

then suddenly begins to break
up and catch fire in the air.

- [Tony] Let's see that again.

A television camera
records the plane

as it appears to go into
a dive during a turn.

Then suddenly, pieces
fall off the plane

and it bursts in the flames

just before it slams
into the ground.

- The incident killed six
people on board the aircraft

and eight people on the ground,

and effectively
doomed the Tu-144

from ever flying outside
the Soviet Union.

- Unsurprisingly, the
Concorde wins the battle

for commercial
supersonic air travel.

In 1976, service begins between
Europe and the Americas,

cutting a six to eight hour
flight across the Atlantic

in half.

For more than two decades,

the Concorde ruled
the supersonic skies

and the Concordski
became a footnote.

The Concorde flew without
incident until 2000,

when Air France flight 4590

crashed just after takeoff,
killing all 109 people on board.

It was found that
debris on a runway

contributed to that disaster.

But what doomed the
Concorde's Soviet cousin?

Our experts are on the
hunt for the pravda,

that means the truth.

[tense music]

When it comes to supersonic
flight, it's all about speed,

but the Concordski may have
been going a little too fast.

- The Tu-144 was rushed
through its development

in an attempt to beat the
Concorde to the market.

Plus, the airplane's
aerodynamic design

just didn't seem as
sleek as the Concorde.

And from what I
see on the video,

I'm very suspicious of a
overstress of the airframe.

In other words, this airplane
was moving too rapidly

and maneuvering too
aggressively to allow its wings

and structure to stay intact.

The pilots, likely, may have
overstressed the aircraft

using aggressive
control movements.

As you can see here,

the airplane begins
to descend downward,

and during the descent,

you can see chunks of
the wing fall apart.

It's a mid-air, in-flight,
structural failure of some sort.

- [Tony] But were those
sudden, aggressive maneuvers

premeditated or an
emergency response?

One claim is the pilot
of the Concordski

was startled by a nearby
French fighter jet.

- The theory was, the
Russian crew was not informed

that this French mirage
jet was in the area,

and that caused a
severe evasive maneuver

that overstressed the airplane.

That's a bit of a
dubious theory to me.

In the video, you
don't see another jet,

you just see the
airplane maneuvering

and then coming apart.

- [Tony] But there's
another theory

to explain the Concordski's
sudden maneuvers

that could be much
more plausible.

- This competition between
who's gonna be the first

to have the best
supersonic commercial jet

is a huge driving factor,

and this occurred at an air show

where you're supposed to
show off your aircraft.

I think it certainly
cannot be ruled out

just how much that may have
played into the pilot's psyche

and his decision to
push this aircraft

beyond its limits.

- [Tony] Despite this
disaster, in 1977,

the Soviet Tu-144
began passenger service

between Moscow and
Alma-Ata Kazakhstan,

but that ended months
later when a new Tu-144

crash landed during
a test flight.

The reason for that crash was
determined to be a fuel leak.

But what really caused the
Paris Air Show disaster

remains a mystery.

- There's never been a
definitive conclusion,

but probably the theory
that fits the best

for what caused this crash

would be a combination
of a pilot error

and design of the
Concordski itself.

- The takeaway?

McMillan and Guzzetti certainly
present a strong case,

but ultimately, the fact is
no one can say for certain

what really happened that
day in the skies over Paris.

Meanwhile, a
supersonic renaissance

may be right over the horizon.

American carriers are investing
heavily in the technology,

though that two and a half
hour flight from New York

to LA is still years away.

- You'd
think perhaps the one time

your car doesn't pose
a risk of any accident

is when it's turned
off and parked.

After watching this video, you
might just wanna buy a bike.

[tense music]

July 24th, 2022, the
streets are quiet

on a hot summer day
in Fuzhou, China.

A man is about to
get on his motorbike.

His bike is next to a parked
car with no driver inside

when CCTV footage captures this.

[explosion booming]
[glass shattering]

Let's see that again.

[tape rewinding]

A great burst of noise

is followed by what
appears to be gas

filling a parked silver car,

then a sudden explosion
sends shards of glass

and bent metal airborne.

[explosion booming]

Moments later, firemen
are called to the scene

to put out the flames,

and luckily, the motorcyclist
gets away unscathed.

- This guy almost gets
his head taken off

when he least expected it.

Something flares in the
car, he turns to look at it.

So you know there was a
noise that alerted him to it,

but there was
nothing he could do.

- [Tony] Pappalardo
says there's no shortage

in history of cars
just blowing up.

In fact, the Ford Pinto
became infamous in the 1970s

for bursting into flames.

Most of those explosions were
caused by rear end collisions

that ruptured the
Pinto's gas tank,

and caused vapors to
spread through the car.

- Usually car accidents are
associated with speeding,

hitting things,
being hit by them.

The idea that a stationary
car poses a threat,

it's kind of alien
and weird to us,

but inside that vehicle,
there's stored energy.

Even a parked car can
be a dangerous car.

- [Tony] So Pappalardo
floats another theory.

Could this have something to do

with the batteries
found in electric cars?

- The batteries inside
electric vehicles

can be prone to be set
on fire in an accident

or even sitting stationary.

In the same way,

gas tanks have been associated
with those things as well.

- After Hurricane Ian hit
Florida in the fall of 2022,

a number of electric
cars caught fire

when their batteries
became waterlogged

and began to corrode.

But why did this car
in China explode?

Our experts go under the hood
of this mechanical mystery.

[tense music]

We see what looks
like a cloud of gas

in the car before the explosion.

So could the lithium
ion batteries

found in electric
cars be to blame?

- Lithium ion batteries
carry their own oxygen.

If they overheat,

they may do something
called thermal runaway.

Before that happens,
they put out some gas,

that gas is explosive.

- [Tony] Martinez says
the batteries overheat,

particularly if they're
used or charged incorrectly

because of what's known
as thermal runaway.

That happens when a
battery cell generates heat

much faster than
it can dissipate.

And that day was
particularly hot in Fuzhou.

But there's a clue
that this may not be

an electric car at all.

There're spraying
the way you would

with a gasoline
fire, with water.

An electric fire would
take a lot more water,

a lot more effort to put out.

- [Tony] We did some digging

and confirmed it
was a gasoline car

made by the Chinese
automaker, DongFeng.

But the mystery remains,
why did it just blow up?

- I wonder if that initial
puff of white smoke

wasn't something like a small
portable lithium ion battery

like in a drone.

And after they've
been flying a while,

those batteries get pretty hot.

There's a chance for
them to start a fire.

It also could be,

somebody was carrying a
gas can around with them

and it allowed the vapors
to build up inside the car,

but that's a really
tough one to sort out.

- The takeaway?

We can't say for sure
what caused this blast,

but since the smoke started

from inside the
passenger compartment,

it's likely it was set
off by a portable gas can

or a lithium ion battery,
not from the car itself,

but from something left
inside, like a cell phone.

And that's our show for tonight.

Thank you so much for watching
and stay safe out there.