Original subtitles

[narrator] Worldwide, 50 billion cameras record our daily lives...

in our hands, in our cars and in our homes.

They capture things that defy explanation.

[woman screaming]

What the hell are we looking at right here?

[man on video] Check this out.

Experts carry out forensic analysis of these unusual events.

Wow! Now, that's a cracker.

[man] Oh!

[woman screaming]

This doesn't make any sense.

There has to be another explanation.

So, what could it be?

[narrator] Coming up, in the world's most secretive state

is this fireball the final moments of an enemy of Kim Jong-Un?

It's possible what we're seeing here is another gruesome execution.

[narrator] Matt Kutcher investigates.

Don't try this at home.

[narrator] In Thailand, is this a boy who has been mummified alive?

[Liberty Vittert] Unlike the ancient Egyptian mummies,

Buddhist monks mummified themselves.

[narrator] Then as film emerges of an apparent fight

between a UFO and ground forces,

why shooting at aliens is never a good idea.

23 of the soldiers that were there

were literally turned into stone.

[narrator] Bizarre phenomenon...

[gasps] Oh, my God!

...mysteries caught on camera.

This is just mind-boggling.

[narrator] What's the truth behind this? Strange Evidence.

Now Changbai, a Chinese town

on the border between the People's Republic Of China and North Korea.

August 3rd, 2020, a man films a strange disturbance

on the other side of the border.

Wow.

This huge fireball, it's out of control.

It just exploded again. Every time we have a boom

there's another big upwelling of flames up into the sky.

[distant shouting]

Kinda crazy.

[George Kourounis] You can hear the concern in the people's voices

as they're watching this fire rage.

[narrator] The Chinese man filming, and his nearby companions,

have no idea what's happening on the other side of the border.

[Carlo Munoz] The North Korean government

really maintains a stranglehold

on any kind of information coming out of the country.

So to see footage like this really is something.

[explosion]

[narrator] Historian Craig Gottlieb looks for clues

and finds this explosion is taking place in a 21st century nation

that's a literal hell on Earth.

[Craig] Folks, this is North Korea,

the most dangerous military, industrial complex on the planet.

[narrator] The communist dictatorship is ruled by tyrant Kim Jong-Un

and his wife Ri Sol-Ju.

Human rights? No. Public safety? No.

Aggressive nuclear program? Yes.

[missile whooshing]

[George] The reality is that there are two North Koreans.

There are the ruling class, the elite, Kim Jong-Un and his family,

who live in conditions of pure opulence.

And then there are the regular people

who are treated very, very poorly.

[narrator] No one in the 25 million person state of North Korea

dares challenge their supreme leader

because Kim is a sadistic killer.

Kim Jong-Un has a long track record

of ordering executions of people he disagrees with.

It's possible what we're seeing here is another gruesome execution.

[narrator] The so-called Great Successor

reserves especially cruel, almost theatrical send-offs

for his greatest enemies.

There was one reported incident of him tossing one of his generals

into a tank of flesh-eating piranhas.

And another incident where a general, who fell asleep during parade,

was shot to death with an antiaircraft gun.

[narrator] Another officer that fell out of favor

is said to have been executed by being torched alive using a flamethrower.

China is extremely wary of their nightmare next-door neighbor.

A fiery execution staged at the border like this

could be Kim sending them a signal

that he has no intention of changing his psychopathic ways.

Is what we're seeing just another North Korean example

of how crushing the regime can be?

[narrator] But Brian Wolshon believes the film could show

a horrific engineering disaster unfolding on the other side.

The story that North Korean propaganda likes to tell

is that the North Korean people are well-fed,

they have quality housing and they're genuinely happy.

But in reality, we know this is not the case.

Housing, in particular, is of poor quality

and in some cases it's actually dangerous.

[Carlo] Families live in a single 250 sq. ft. room.

Now, because of the cramped conditions

and sort of this shanty town-like atmosphere

fires are extremely common.

[narrator] Hollywood pyrotechnics expert Matt Kutcher

has over 35 years' experience with explosions.

He believes the film shows not one blast but many.

In this case, you definitely see an explosion, right?

And then that explosion seems to be setting off other explosions throughout.

So I think what we're witnessing here

is cylinders have filled up with compressed gasses, and they're blowing up.

See, I think each one of these bursts is another bottle going,

or another pressurized vessel, right?

I think that's what we're witnessing here.

So calmness, calmness, calmness and then bang,

another burst, another bottle goes off.

Or something else that's under pressure, right?

I think the way it goes up and dissipates,

I think it's probably either natural gas or propane.

I think we could take some bottles

and actually try to blow them up

and see if we can recreate something that looks like this video.

[narrator] Reports from 2019,

suggest that just over a quarter of North Koreans have electricity,

and those that do are reported to be limited to a few hours each day.

People in the North Korean countryside have to come up with other solutions

if they want to heat and cook to stay alive.

In that video, it's certainly a mystery

-to what's blowing up there in North Korea, right? -Yeah.

But in rural areas, probably in that country,

they're actually using some kind of propane systems for either cooking

-or whatever else they have to do, right? -Right.

So if we use these to simulate the propane bottles,

high-pressure gas, and there's a cooking fire for instance,

that fire generates enough heat,

that heat broaches this bottle.

Once it does that the bottle explodes. You see that in the video.

-Right. -But maybe the heat from this one

sets of the next one and the next one... Pause,

heat generates again, blows up the rest of 'em.

So I think what we're gonna do is break these bottles, create a flame source,

a safe place to stand, and see if our experiment will work.

-Big chain reaction. -Big chain reaction. Exactly.

-Nice. -Well said. All right, son. Let's go.

We're gonna need to build just two sets of kickers.

Peel off all the paint and that'll be the safe zone of which we'll hide behind.

Then we're gonna take a yellow and blue bottle.

Bring me three of each, please.

[narrator] A propane tank holds more than 30 kW of energy

for every pound of compressed gas inside.

So, what I'm about to do you shouldn't film. Don't try this at home.

[narrator] Matt makes a fuse on the floor,

simulating an accidental cooking fire in a North Korean apartment.

[Matt] Okay, here we go. Something's definitely gonna happen.

[narrator] The team take shelter.

[Matt] All right, ready? Is everybody rolling?

Nice. Go ahead and light the pilot, son.

[Matt] Yeah, look that heat's starting to build.

[narrator] Coming up, can Matt and his team simulate a kitchen nightmare?

-I can feel that heat. Can you feel the heat change? -Yeah.

[Matt] That's pretty cool, right? Wow!

[narrator] And this is no ordinary statue.

Thai villagers make a disgusting discovery.

The face of this child, it looks like an expression of fear.

Utter fear and almost desolation.

[narrator] On the Chinese, North Korean border

a Chinese man films a mysterious explosion

rocking the secretive nation on the other side of the Yalu River.

Explosives expert Matt Kutcher suspects the blast could be evidence

of a terrible propane tank disaster

in the cramped housing projects

dictator Kim Jong-Un forces on his people.

All right, light the accelerant.

[explosion]

[Matt] Wow, that's getting hot. Look at that smoke.

You can really feel the heat now.

[narrator] Matt puts six propane tanks into a burning ring of fire.

As the flames leap higher the temperature of the cylinders increases,

the gas pressure builds, until...

Okay. Yeah, that's what we saw in the video. That's great.

[narrator] At temperatures as low as 120 degrees the propane tanks breach

releasing a devastating, oily, liquid-expanding vapor explosion

known as a bleve.

[explosion]

-[Matt] That worked out pretty good, huh? -[man] Yeah, really good job.

[narrator] The explosion releases a burst of flames

very similar to the conflagration seen in North Korea.

The fire starts and it's gonna start to create heat.

You can see it developing really well.

[Matt] The heat's building, which is creating pressure in those vessels.

So it's building and building and building, and bang, now they explode.

The pressure's released, the flame there captures it. What an explosion!

Great experiment to do here in the shop,

but not something you want to happen inside your house.

[narrator] Engineer Nick Householder consults maps of the area

and finds a cramped and overcrowded housing project

located near the source of the blast.

Reports from those on the ground

indicate that this was a house fire

that spread to a liquid propane gas cylinder on the side of the house.

This caused a chain reaction with the other houses around it

resulting in a series of fires and a series of explosions of compressed gas cylinders.

In this particular case, the entire row of houses was leveled

with nine fatalities.

Nine people died, but guess what the authorities were concerned about?

Well, in North Korea one thing, their leader.

[narrator] Every home in North Korea

must display portraits of their leaders on its walls.

What they wanted to know was did the families go back into the houses

during the fire and rescue portraits of their former leaders?

And to add a twist to this story, in typical North Korean style,

the owner of the house where the fire started

was actually arrested by the government for embarrassing the nation.

[narrator] Now Thailand's remote Surin province.

January 27, 2021.

A person with a camera follows villagers into the jungle

to find an extraordinary makeshift shrine.

It looks like it's a statue of a little boy.

It's got a head, two eyes, two ears and a mouth.

[narrator] But this image hasn't been carved by human hands.

Locals claim it was discovered fully formed in the forest

by a villager out looking for wild mushrooms.

[Linda] It's really uncanny. The more you look at it, the more it looks like a boy

actually just sort of sitting there.

[Liberty] The face of this child,

it looks like an expression of fear.

Utter fear and almost desolation.

It looks like the figure was kneeling, maybe begging for life.

Where did this come from?

I mean, this is creepy. I don't wanna call it repulsive

'cause it looks like the body of a young boy,

but the skin, it looks mummified.

[narrator] Journalist Linda Rodriguez McRobbie

finds evidence of a gruesome religious practice

which might explain the strange shrine.

There's a phenomenon in Buddhism called sokushinbutsu,

and essentially it refers to someone who's been able to mummify themselves.

[narrator] Mummies are found in cultures all over the world

from ancient Egypt to Peru.

But in Southeast Asia these Buddhist bodies

are mummified in a very different fashion.

[Liberty] Unlike the ancient mummies of Egypt

these guys weren't involved after death.

These Buddhist monks mummified themselves when they were alive.

[narrator] Monks practicing sokushinbutsu

put themselves through unimaginable torture

with the aim of helping humanity

reach a state of enlightenment.

Sokushinbutsu is a sacrificial act

and it's done in emulation of a ninth-century monk called Kukai.

The practitioners, the people who are successfully able to do it,

believe that they are sort of carving a path to salvation for all of mankind

through this personal, very extreme sacrifice.

[narrator] Biologist Leslie Samuel

finds an extraordinary account of one Buddhist holy man who undertook the ritual.

It's really extraordinary, over a number of years

the monk basically eliminated fat from his body through a strict diet.

Things like nuts, wood and berries.

Severely limiting his water intake,

he'd drink a kind of tea that was made from a poisonous tree.

All this starvation, dehydration, poisoning,

the goal being to prevent his body from decomposing after death.

[Linda] Once he's reached a sort of state of emaciation and dehydration,

he is buried alive in a pine box for his last days on Earth.

He had a bamboo shoot for a breathing tube, it allowed him to breathe.

And he had a bell that he could ring to signal that he was still alive.

[bell ringing]

Once the bell stops ringing, then the other monks seal up the tomb.

[narrator] The bodies of these self-made mummies

are left underground for a thousand days.

After the thousand days were up, they'd bring the body back up

and check to see whether or not it had decayed

and if the body was preserved well enough

then they would go ahead and enshrine it.

[narrator] Self-mummification is outlawed in some Buddhist countries,

but one famous Thai monk is said to have gruesomely succeeded in 1973.

On the island of Koh Samui there's a shrine to a monk named Luang Pho Daeng,

and he's believed to have mummified himself and died while meditating.

[narrator] Luang Pho Daeng's remains

are displayed in a glass case at Wat Khunaram.

The only part of his body seen to fully decay are his eyes.

Monks decide to cover the empty sockets

with a pair of designer sunglasses.

You know, if this thing is not a statue, is it mummified?

Has it been there forever, is it ancient?

[narrator] Biologist Steve Potvin looks closer

at the bizarre boy in the jungle

and believes he sees signs of life.

[Steve] Zooming in close on its shoulder

it almost looks like there's something alive there. Maybe that's an egg sack.

Maybe something burrowed in it.

[narrator] Coming up, eaten from the inside out.

Are villagers looking at the husk of a human?

[narrator] And although the U.S. military are ordered not to fire on UFOs,

Arizona citizens seem to have other ideas.

This thing definitely flew into the wrong valley.

In the Thai jungle, a weird object shaped like a young boy in agony

is full of tiny insects.

[Steve] Are these people looking at an empty shell

of what used to be a human being?

[narrator] But entomologist Kevin Kasky looks at the texture of the object

and believes these insects didn't set up home in a boy,

they built the boy-shaped structure themselves.

Thailand is home to over 150 species of termites.

Some of them create very extravagant, very large termite mounds.

This could be one of those structures.

[narrator] Termites are unsung under lords of the Earth.

For 250 million years, these tiny tower builders

have survived in colonies up to three million strong.

They operate collectively like a gigantic hive mind.

Termite mounds can take four to five years to build

and they're incredible feats of engineering.

The tallest termite mound recorded was 42 feet high,

found in the Republic of Congo.

From their perspective, it's taller than any skyscraper

that we have in our big cities.

The mound is a continuously-morphing, complex contraption,

specifically designed to regulate temperature.

A, for instance, one section of the mound is too warm,

the termites will follow their senses to that section

and adjust the mound to reduce temperature.

By creating tiny ventilation passages,

the pores of the nest manage gas exchange

in ways that are similar to how human lungs function.

[narrator] There are millions of termite nests all over the world.

One of the oldest has been dated to as early as 2000 BC,

making it as old as the pyramids of Egypt.

But none have been recorded taking on the shape of a human.

[Steve] There's no specific shape

that the termites try to make these things,

it's really just chance.

[narrator] The random shape created by these termites

seems to have grown into something that looks like a boy.

It's not about the termites. The termites haven't made a statue of a child,

it's about us and what we want to see.

[narrator] Locals believe this bug-built boy

is a magical manifestation of Ai Khai...

a popular prankster spirit who brings good fortune.

This termite mound might look like a boy for now,

but termite mounds are a work in progress constantly.

So, while this looks like a boy or a child now,

in a few months, it might look like something completely different.

[narrator] Now...

...the high desert

outside Wikieup, Arizona.

March 23rd, 2019.

A mysterious object appears in the darkness.

There's something white and bright flying through the night sky.

[Tim] It's moving erratically, it's changing direction.

It's speeding up, slowing down.

[narrator] Then, gunfire erupts.

[gun firing]

Wow! That's a lot of [chuckles] gunfire.

It's just like bullets flying everywhere.

[gun firing]

It looks like a war zone.

[narrator] But the unidentified object

easily dodges the fire coming up from the ground.

It's like it's taking evasive maneuvers

to avoid the tracers.

There's an intelligence there.

[Carlo] It's almost dodging the bullets,

just flying in between them

seemingly unscathed. It's pretty amazing.

The big question is what is that white glowing object?

Who's firing at it and why?

[narrator] Journalist Jeff Wise believes this flying object

is not a normal aircraft.

[Jeff] This hovering white dots

seems to be moving in a way that we can't really explain.

To have to ask, "Is this a UAP?"

"Is that an alien craft?"

What are we looking at?

[gunshots]

Is this the military reacting to maybe a UFO?

[narrator] UFOs are no longer regarded as myths.

The US government now admits

that weird objects with unexplained capabilities

have been known to the military for years.

There have been a number of sightings in the sky

by military pilots that have not been able to be explained.

Could this be something else

that is one of these Unexplained Aerial Phenomena?

[narrator] As the US government throws open

previously classified UFO files,

there is increasing evidence that firing

on one of these objects is not a good idea.

A recently declassified CIA document,

recorded an incident similar to this

that took place in Siberia in 1993.

[narrator] The report describes a low-flying

saucer-shaped object

that crashes near a military unit

out on a training exercise.

As the soldiers approached the wreckage,

they reported that five small humanoids

got out with large heads and black eyes.

[narrator] Then it gets even weirder.

The five beings merge into a buzzing, hissing ball of white light,

which becomes a bizarre and devastating weapon.

The reports says that 23 of the soldiers

that were there, were petrified.

They were literally turned into stone.

Only two soldiers survived the incident.

[narrator] The report claims that petrified soldiers

are transferred to a secret research unit near Moscow,

where scientists determine their remains

have a molecular structure like limestone.

[Tracy] I think, the fact that they were unable

to figure out what this was, is very unnerving

and unsettling to a lot of people.

[narrator] Coming up...

a citizen army prepares to fight the ultimate intruder.

[explosion]

Is what we're seeing, uh, some kind of militia?

That we came across a UFO invader?

[narrator] And in Loch Ness, a shadowy shape

seems to be targeting kayakers on the beach.

It's moving towards the shore where there's a lot of folks.

[narrator] In the night-time skies of the Arizona desert,

-a man films as a bright object appears. -[bullets whizzing]

And gunmen on the ground open fire.

[Carlo] Whoever's shooting at that thing,

they're not doing a very good job of it.

They're pretty much missing very badly.

[narrator] Military journalist Carlo Munoz

suspects these shooters are not soldiers,

but could be members of a militia.

[gunshots continue]

The have the body armor, they have the weapons.

They sometimes participate in very military-like training operations.

Is what we're seeing, uh, some kind of militia

that came across a UFO invader?

And decided to shoot first

and ask questions later?

When people get scared, they wanna defend themselves.

It's natural.

[narrator] American neuroscientist, Sam Harris

says he's been approached by people

connected to the US government

seeking advice about how best to disclose

an alien presence on earth to the public

without the news inciting panic or chaos.

UAP events being not from this planet,

I don't think we're ready to hear that.

That would shake the science community to its core.

[narrator] Official confirmation that aliens are here

would be the greatest event in world history,

upending not just science, but religion,

politics and the entire global economy.

-[people shouting] -When whatever government entity

adds data dump of information

that was previously classified,

there always is a chance that it can create mass hysteria.

[narrator] If this video is evidence

of how ordinary Americans react to a flying saucer,

the government has a lot of work to do.

This is kind of the nature of human beings.

When they are feeling threatened, they fight.

This thing definitely flew into the wrong valley.

[narrator] Craig Gottlieb discovers audio files

which reveal that the machine guns,

this time, are not being fired in fear.

[man] Yeah! [laughs]

Let's go, plane!

[Craig] It's like a fun shoot,

where someone's flying a drone at night on purpose

and other people on the ground

with legally registered machine guns

and they're trying to shoot the thing out of the sky.

-[bullets whizzing] -[Jeff] Even though all these people are just

having the time of their life, blasting away,

it turns out to be really hard to shoot down a drone.

[narrator] It takes a fortune in ammunition,

but eventually the shooters do manage

to take down the drone.

-[people cheering] -[man] Oh, all right.

What we're seeing is, some people that are, uh,

spending a lot of money to be ready.

To be ready for what? I... I don't know.

Are these people preparing for a UFO invasion?

[narrator] Pentagon reports indicate UAPs

are frequently harassing US Navy vessels

in the Atlantic, the Pacific and in the Persian Gulf.

So far, there is no evidence the military has fired

on these potentially hostile adversaries.

Perhaps because the retaliation would be swift and brutal.

The government truly does take UFOs seriously.

I do think, perhaps the next generation of warfare

may originate from Space.

[man] Let's go, Plane!

[narrator] If these people are preparing

to lead a citizen defense against alien invasion,

they might be embarking on a suicide mission.

If this is from somewhere else

and not on this planet,

chances are it's a lot smarter than we are.

Is it a really good idea to be shooting guns

and ammo at this thing? I don't know.

[bullets whizzing]

[narrator] Now, Scotland.

Loch Ness.

August, 2021.

A drone operator films a party of kayakers

whose boats are on the beach.

Water is so dark. What's splashing there?

Oh, jeepers creepers. That's pretty big.

There's something lurking just off the shore.

[Roland] It look like it's moving under its own power.

It really makes you wonder what it is.

It's moving towards the shore where there's a lot of folks.

[narrator] The group on the beach have no idea

there is a huge object in the 23-mile long Loch.

Apparently, just feet away from them.

It looks like it could be a large reptile.

Is there a possibility that this guy

has captured footage of the Loch Ness monster?

Here we have excellent reference points...

canoes on the shore.

We see that the object is about two canoe lengths.

That makes it about 30 feet long.

[Eric] If this truly turns out

to be an unknown large creature,

it's a game-changer.

[narrator] Coming up... is this proof

the Loch Ness monster is a descendant

of a shell-backed prehistoric predator?

Archelon is a real force to be reckoned with.

[Linda] Not the kind of creature you'd wanna meet

if it was hungry.

[narrator] And off a tropical island, is the sea

draining into a subterranean abyss?

[George] If you were to take Niagara Falls

and submerge it under the Indian Ocean,

that's basically what it looks like here.

[narrator] In the dark waters of Loch Ness,

by volume, Scotland's largest lake,

a drone captures an enormous shadowy shape

near the shoreline.

Journalist Linda Rodriguez McRobbie wonders

if the creature may be ready to come ashore.

Interestingly, some of the sightings of the beast

have actually been on land.

Now that sort of changes the picture

of what we think this creature could actually be.

[narrator] July 1933,

George Spicer and his wife were driving past the Loch

when something huge blunders across the road in front of them.

The couple describes what they said was a gray,

kind of, hump-backed beast with flippers.

[narrator] Spicer estimates the beast to be some 25 feet long,

close to the size of the shape in the drone footage.

Other accounts have described something that sort of,

waddles along in what could be flippers or webbed feet.

[narrator] Marine biologist Eric Hovland

discovers a remarkable theory.

Professor Henry Bauer of Virginia State

studied life in the Loch,

which was carved out by glaciers during the last ice age.

He believes Nessie could be a super-sized

versions of a well-known shell-backed reptile.

Professor Bauer leans toward the theory

that this was, in fact, a giant sea turtle.

Now perhaps sea-level changes over time

have trapped this species

and established it in Loch Ness.

[narrator] Turtles can live for more than a century

and are able to navigate both on land and in the water.

Let's explore further the theory that this is a giant sea turtle.

Wouldn't we have seen it by now?

I mean, it is giant after all.

[narrator] But sea turtles have special powers

which could allow them to stay hidden.

An amazing thing about sea turtles is they can stay under water

for up to seven hours without taking a breath.

[Eric] That means you only have a brief moment to see

a turtle when it comes to the surface,

takes a breath and dives back down.

[narrator] Some sea turtles can manipulate

their metabolism to conserve oxygen,

slowing their heart rate to just one beat every nine minutes.

When turtle species hibernate, say to the bottom of a lake,

they can remain submerged and buried in the substrate

for months at a time.

Turtles, even giant turtles, are pretty perfectly designed

to hide out in the muddy bottom of Loch Ness.

[Hannah] So if the Loch Ness monster

is of the same lineage as a sea turtle,

then it's... it's not really that surprising

that it's quite hard for us to find.

[narrator] Former NYPD Image Analyst, Conor McCourt,

looks for evidence this image could show

some kind of titanic turtle.

So the kind of things you would look for

is some kind of shell, some kind of flippers.

Uh, right here, we see what could be a flipper

and this area which could be a shell.

Well, when compared to the canoe on the beach,

it would mean that the shell

is between 10 and 15 feet long.

If this is a turtle, this is a very big turtle.

[narrator] Zoologist Roland Kays

wonders if the monster could be related

to a giant prehistoric sea turtle,

the mighty Archelon.

Archelon weighed something like 5,000 pounds

and was an omnivore.

Archelon is a real force to be reckoned with.

[Roland] Archelon had a sharp beak

that scientists think they used to attack giant squid.

It must've been quite a scene in the prehistoric seas.

Not the creature you'd wanna meet if it was hungry.

[narrator] A sonar survey in October 2020,

seems to confirm the presence of a single animate object

up to 20 feet long.

[Linda] In the sonar image, you can see this kind of...

oblong, whitish shape

that's at the bottom of the lake, 600 feet down.

[Hannah] This huge creature was keeping pace

with the boat as it was tugging the sonar equipment.

So there are actually some really exciting evidence

to suggest that maybe there is living in Loch Ness.

[narrator] The object captured on the drone

never broke the surface,

so the oblivious kayakers on the beach could not confirm

what the monstrous shape really was.

[Linda] Maybe there is something there.

And maybe with all the technology

that we have available to us now,

we'll finally find out what it is.

We are not giving up on the Loch Ness monster and Nessie quite yet.

[narrator] Now, Mauritius,

a vacation-paradise island

in the middle of the Indian Ocean.

2018...

A passenger is filming from a small aircraft.

Whoa! Oh, my!

[George] It looks like the bottom of the sea

has just opened up and then water seem to be just...

pouring down into the abyss.

[Sarah] We're staring into some sort of hole

which is sucking the ocean down into it.

[narrator] The island itself seems to be falling away

as the water around it gushes down.

The sea is just disappearing.

So what exactly are we looking at here?

[narrator] Coming up...

mysterious Mauritian pyramids

and the legend of an Atlantis-style apocalypse.

Is it possible that the island of Mauritius

is being sucked into the ocean?

[narrator] A man flying over the tropical paradise of Mauritius

films what appears to be the ocean falling into an abyss.

[Sarah] It's a powerful, powerful video.

Is there like a waterfall within the ocean?

[George] If you were to take Niagara Falls,

and submerge it under the Indian Ocean,

that's basically what it looks like here.

[narrator] Incredible as it may sound,

scientists have found evidence of titanic waterfalls

under the surface of the seas.

In the swirling currents between the Greenland Sea

and the open water of the North Atlantic,

oceanographers have uncovered an incredible secret...

the Denmark Strait cataract.

[Hannah] In the Denmark Strait,

many currents converge and they actually create

the world's largest underwater waterfall.

[Orelon] You have very, very cold water

that's flowing into warmer water.

That cold water is going to dive beneath

that warmer water, simply because of density.

[narrator] At below 36 degrees,

the cold waters streaming from the east

is significantly denser than the warmer Atlantic waters to the west.

The icy cascade plunges some 11,500 feet

down into the frigid depths,

carrying 123 million cubic feet of water every second.

That's more the 12,000 times

the flow rate over Niagara Falls.

But to go look for it, you'll need a submarine.

It starts 2,000 feet below the surface.

It's three times the height of Angel Falls in Venezuela.

Uh, this is an enormous thing that's under water

but hardly anyone sees it because of where it is.

[George] This thing is absolutely massive.

And you could sail a boat right over top of it

and never know it was there.

[Sarah] Could there be something similar going on in this video?

Could this be another waterfall under the ocean?

[narrator] But George Kourounis is skeptical

that a sub-surface waterfall

can explain the extraordinary video

from tropical Mauritius,

where the sea maintains an average temperature

of between 72 and 84 degrees.

The only reason why we have an underwater waterfall

in the North Atlantic

is because we have two different densities of water

interacting with each other.

In the Indian Ocean, off the coast of Mauritius,

we don't have that effect.

[narrator] Meteorologist, Orelon Sidney

looks at Mauritian archives

and finds that although the island officially

was first settled in the early 17th century,

it has a much older secret history

that has been lost to the ocean.

In the past, Mauritius has been a lot bigger.

Back in the day, we're talking about an island

the size of Japan.

Today, we're talking about an island

that's 30 miles by 40 miles,

so much, much smaller.

[narrator] Mysterious pyramids dot the landscape

on the southern side of the island.

Local Mauritian historians

insist they date to the 19th century.

But researchers like Antoine Gigal

identify them as much older.

Some link them to Kumari Kandam,

a legendary land mass

said to have been lost to the sea

like an Indian Ocean Atlantis.

Most of the undiscovered things on this planet,

are actually under the water.

Is it possible that the island of Mauritius

is being sucked into the ocean?

[narrator] Historian Tony McMohan

finds geological reports that show the island

home to over one million people,

is indeed in peril.

[Tony] What's actually happening here

is that Mauritius is literally crumbling bit by bit,

from it shelf deep down to the bottom of the ocean.

[narrator] But it's a gradual process

of sediment running off the shelf.

A process that creates an optical illusion

as you fly over the clear, blue waters of its coast.

[George] When you look at this stretch of water,

particularly from above, in a helicopter,

it really takes on that appearance

that the water is tumbling into a deep trench

and it's a bit of an illusion.

Mauritius will eventually disappear.

The only good news is, it'll take million of years.

[narrator] Slowly but surely, all of the island

will slide down onto the deep ocean floors

some 13,000 feet below.

And this erosion is visible from the air.

This is actually quite a scary thing to look at.

[Orelon] Don't buy beach-front.

'Cause it look like the island

is literally sliding away into the ocean.