Original subtitles

NARRATOR: An ancient volcanic eruption in Italy

provides an unprecedented revelation

of the brutality of Roman life.

- These were unbelievably violent affairs,

with limbs, blood and guts flying all over the place.

NARRATOR: A devastating tsunami in India reveals a long-lost legend.

- The disaster removed six feet of sand,

exposing some massive rock sculptures.

NARRATOR: A horrific earthquake in Mexico

opens a door to a secret chamber in an Aztec temple.

- They also discovered a pit of human bones - adults and children.

NARRATOR: All over the world, incredible discoveries

are being revealed by devastating events.

Floods, earthquakes, droughts.

Hurricanes, volcanic eruptions.

Trails of destruction expose long-lost mysteries.

This is Discovered by Disaster.

NARRATOR: On August 24th, 79 CE,

after lying dormant for centuries...

..Italy's 4,000ft Mount Vesuvius erupted.

The enormous explosion took many of the citizens

living around the volcano by complete surprise.

(screams echo)

- In the initial stages of the eruption

fine ash followed by pumice, a porous volcanic rock,

began raining down on the people of Pompeii,

a town about five miles from Vesuvius.

MAN: An ominous ten-mile mushroom cloud appeared in the sky.

And then the eruption took a turn for the worse.

Avalanches of superheated rock began cascading down the volcano

while toxic ash and gases

spewed from Vesuvius's mouth and covered the entire countryside.

NARRATOR: While the vast majority of Pompeii fled...

..those who remained were subjected

to a deadly concoction of toxic gases

and hot rock and ash

that buried the entire town in up to 23ft of volcanic debris.

- It's estimated that 2,000 men, women and children of Pompeii

died in this disaster -

some of them asphyxiated as a result of the volcanic gases,

while others died from being blasted by extreme heat.

(screams echo)

NARDI: Following this, a tsunami of hot rock and ash covered them all.

It's almost unimaginable.

- That's the thing though. It's almost unimaginable

because we can imagine it.

And that's because of the dozens of feet of ash

covering the town where everything has been perfectly preserved

since that fateful day over 2,000 years ago.

LEONARD: The victims were initially covered in ash.

But over time this ash hardened,

preserving the position and outline of their bodies,

leaving behind what are essentially human plaster moulds.

- The disaster created an archaeological marvel

that we're still exploring and studying today.

Although Pompeii was first discovered by a grape farmer

in the 18th century, it has been continuously excavated ever since.

The 2,000-year-old tragedy provides an endless amount of insight

into the life and times of ancient Romans.

NARRATOR: In 2024, archaeologists excavating

a section of central Pompeii

were stunned when they came across the remains of a man and a woman.

- It's not like finding remains is entirely unexpected

but, as an archaeologist, when you do find human remains,

you always take some time to think about the individual.

Who were they? And, in this case, it appears to be

an elderly man and woman seeking shelter in an alleyway.

- They're lying in the alley of what the Romans called an insula,

which essentially meant an entire city block.

In this insula, there appears to have been a bakery

as well as several family homes.

And these remains were found in front of a doorway

leading into one of these houses.

- The space where they died is actually free from the debris

that fell during the first phase of the eruption.

But the bodies are covered in a grey lapilli

that fell during the second phase.

Lapilli are molten or semi-molten pieces of lava.

So you can only imagine the kind of damage they would do to your skin.

- So they probably found this place

and, seeing that it was relatively free of volcanic debris,

they hoped in vain that it would provide some form of protection.

NARRATOR: In a room adjacent to where the elderly couple was found,

archaeologists have previously found cups filled with pigment.

NARDI: The pigment was probably being applied to the walls.

The Romans were very fond of frescoes,

which is a method of applying paint onto fresh plaster,

often with elaborate images or scenes.

In Pompeii, there are hundreds, if not thousands,

of gorgeous frescoes in people's homes, including this one.

- What's interesting here is that there are drawings

that haven't been filled in with colour yet.

The outlines have been drawn, but the fresco isn't painted.

There is also old scaffolding lying about the place,

the kind you see workers use for construction.

- So my guess is that when Vesuvius erupted,

there were painters here hard at work.

We do know that an earthquake had occurred

in the days preceding the eruption.

So it could be that handymen and painters

were already repairing damaged walls and repainting frescoes.

Maybe they were about to apply the pigment when the disaster struck.

CANTOR: It isn't just beautiful frescoes that were being created.

There are funny-looking stick figures drawn on the wall.

What are these things?

NARRATOR: On the wall are images of two people playing with a ball

as well as two boxers

with one seemingly knocked out

prostrate on the ground.

- These are funny little sketches.

They seem pretty innocent, as if they were drawn quite quickly

and different from the frescoes that we see

everywhere else in ancient Rome.

- Frescoes were made not just for their beauty,

but also because, in a society where most were illiterate,

it was through images that information,

myths and stories could be told.

But these little triangular stick figures

were obviously not drawn as decoration.

What we're looking at here is graffiti.

- Today, you see graffiti tagged all over the place.

It depicts everything from political opinions to art, humour and sadness.

It often reflects the spirit or problems of a time

as well as the values of a society.

And just like in today's cities, ancient Rome was no different.

People were active graffiti artists.

NARRATOR: All over Pompei are 11,000 pieces of graffiti,

covering a wide variety of topics.

Political candidates and messages,

results from gladiatorial battles,

personal insults, declarations of love,

and even just simple jokes adorn the city's walls.

CANTOR: One joke reads, "I'm amazed, oh, wall,

that you haven't fallen into ruins

since you hold the boring scribbles of so many writers".

Or take this rather heartwarming one:

"We two dear men, friends forever, were here.

If you want to know our names, they are Gaius and Aulus."

But it's not all love and humour.

There are also intricate descriptions

of battle between gladiators

seen on a wall in the great theatre of Pompeii.

NARDI: Just like today, people felt the need

to share a rather wide variety of feelings and thoughts.

But these little stick figure graffitis

are quite different from all the other ones.

So what's going on?

NARRATOR: Archaeologists also discover

three small hands next to the two boxers.

- The graffiti on this section of the wall

is only about 1.5ft above the ground.

And these drawings are very simplistic -

different from the detailed, impressive images

depicting gladiatorial combat.

Also, considering how small these hands are,

I think it's safe to say that whoever drew on this wall

was a child.

NARRATOR: In a nearby courtyard of the same insula,

more charcoal graffiti is found.

However, the art has taken on a less playful theme

with what looks like hunters spearing animals

and two men engaging in combat.

- The animals have bristles drawn on them,

which makes me think they're wild boars.

And, when also considering the two men squaring up to each other,

I'm not so sure those two stick men with spears are hunters at all.

- We know that one of the principal forms

of mass entertainment in ancient Rome

was for people to head down to the local amphitheatre

for some good old gladiatorial combat.

These were unbelievably violent affairs

with limbs, blood and guts flying all over the place.

- But what's lesser known is that citizens of Rome

also had a special place in their hearts

for pitting man against beast.

Fighters specifically trained for the task of taking on a wild animal,

like a lion or bear, to the death.

NARRATOR: Venationes were events of such immense popularity

that the entire Roman empire

was scoured for crocodiles, hippopotamuses, panthers

and other ferocious beasts.

- The fighters entering the ring with lions and tigers

were known as bestiarii and were in a category separate from gladiators.

Regardless, they certainly made quite the impression

because this child of Pompeii

decided to tag a wall with a scene from a venatio.

NARDI: The child was likely doing so from memory

and not from his imagination.

Children, after all, did attend these events.

The fact that they were drawing gladiators

confronting each other in the arena and bestiarii taking on wild boars

gives us a lot of insight into the mentality of ancient Romans.

- In ancient Rome, violence was a popular source of entertainment

and children would have witnessed an immense amount

of bloodshed and brutality.

They would have seen gladiatorial combat, animal combat,

but also the public executions of criminals of Christians of slaves.

You have to wonder what that would do to a child's mind.

- Well, it did enough for this child

to want to immortalise the fighting on a wall.

But, more importantly, it both normalises violence

and encourages children to look up to those

who are in the position to carry out that violence.

NARRATOR: Rome was reliant on force

as a means to acquire new resources and territory,

as well as to enforce the payment of tribute

on those living in the conquered provinces.

- How do you get people willing to kill and maim in the name of empire?

You need to familiarise them with brutality, romanticise it,

and glorify forces of virtue when applied in the right situations.

- At its peak, the Roman military numbered almost half a million men.

Think about what's needed

to maintain a fighting force of that size.

Not just the logistical sophistication required

to arm, feed and transport those men,

but the culture required to keep them fighting.

NARRATOR: Next to the bestiarii

the child has drawn a simple eagle's head.

- The eagle is probably the symbol most associated with ancient Rome.

It was the emblem of imperial power

and represented courage, strength and immortality to the Romans.

- What this graffiti shows us is not just that this kid

was caught up in the propaganda of the empire.

This was an intensely militarised society

and children were naturally very much a part of it.

NARRATOR: Today, this is the most densely populated

volcanic region on the planet.

Around three million people live close enough to Mount Vesuvius

to be impacted by an eruption.

And, of them, upwards of 700,000

live in what is known as the death zones.

It last erupted in 1944,

but the last major eruption occurred in 1631.

So it is due for another big one.

When that will happen... only Vesuvius knows.

NARRATOR: December 26th, 2004.

Along the coast of Tamil Nadu in southern India,

people go about their morning under clear blue skies and little wind.

- What they didn't know was that at 6:29,

an enormous undersea earthquake, magnitude 9.1,

struck just off the coast of Sumatra.

It was one of the five largest earthquakes ever recorded

since the invention of the seismograph.

Enormous waves travelling at around 500mph

began spreading out from the epicentre

and across the Indian Ocean.

When they eventually reached shorelines thousands of miles away,

the devastation was total.

Some coastal communities as far as East Africa

were hit by massive tsunamis of up to 30ft.

225,000 people across South and Southeast Asia lost their lives.

The tsunami destroyed fishing grounds

and poisoned valuable farmland with saltwater.

In south India, over 10,000 people perished,

mostly in and around the city of Chennai in Tamil Nadu.

This area was devastated.

NARRATOR: Just under 40 miles south of Chennai, India,

in the town of Mahabalipuram,

the force of the tsunami had uncovered several massive boulders

that had been buried under the sand for years.

- The disaster had,

in effect, removed six feet of sand from the beach,

exposing some very big boulders.

But these were no ordinary boulders.

These were massive rock sculptures.

NARDI: One boulder, about the size of a man,

was carved into the shape and face of a lion.

And on the back side are images of an elephant and a horse.

The elephant is carrying what's called a howdah

which, in Hindi, means a carriage or seat

that would be used for riding an elephant.

- Where the writer should be sitting is instead a little space,

a small hole carved into the rock.

My guess is that this nook is an altar

where you can place a statue of a deity.

In Hindu mythology, the god Indra, the king of all gods,

is often depicted atop an elephant.

So this boulder probably functioned,

at least partially, as a shrine to him.

NARRATOR: On the other side of the boulder,

there was a similar hollow carved out of the lion's chest.

- Again, this would have been a mount

for a god or goddess - in this case Durga,

the protective mother of the universe.

She's often depicted riding a lion,

so this was likely a shrine where they can worship her.

But the craftsmanship here is incredible.

Who created these magnificent altars?

NARRATOR: Mahabalipuram is an ancient city

that began rising to prominence around the 1st century CE.

- As a testament to how old this place is,

ancient Chinese, Persian and even Roman coins have been found here.

But what this also means is that it was a great maritime city

engaged in trade with cultures from all over the world.

NARDI: Mahabalipuram was and remains a Tamil city.

The Tamil people trace their ancestry back thousands of years

and continue to inhabit large parts of southern India and Sri Lanka.

NARRATOR: Other boulders unearthed by the tsunami reveal carvings

with inscriptions depicting animals and gods, some written in Tamil.

NARDI: One of them speaks to the existence of a Subramanya temple

located in a little hamlet nearby.

NARRATOR: Inspired by the ancient text,

archaeologists arrive at the hamlet

and begin excavating a mound that has remained undisturbed,

likely for centuries.

- They find what looks like a fairly large wall constructed out of stone.

And then, on the other side of that wall,

they find a rectangular building

that was built using two different kinds of bricks.

- The lower part of the foundation is made of large bricks,

while the upper part is made of narrower, smaller ones.

This probably means that whoever built this

did so at two different times.

- And given the inscription on the rock,

I'm going to assume this foundation is a plinth,

which is another word for a square slab at the base of a column.

And, in this case, at the base of what might be a temple.

NARRATOR: While continuing to excavate,

the archaeologists find what appears to be a six-foot spear

carved entirely out of granite, placed on a row of lotuses.

- The spear and lotuses are associated with Lord Subramanya,

the Hindu god of war.

Considering all these discoveries, there seems to be several sites

with a clear and pretty heavy religious significance.

Did the tsunami uncover some sort of religious centre?

- According to a famous legend,

when approaching Mahabalipuram,

sailors could see what was known as the Seven Pagodas.

A pagoda is a tall, tiered temple,

the kind that you see all over South and East Asia.

When the seamen saw them appear on the horizon,

they knew they were about to arrive at the famous port.

- The legend continues on to say that one day

the god Indra grew jealous of Mahabalipuram's beauty.

And so he destroyed the pagodas with a powerful storm.

This was always considered a myth.

But could there be more to this story than previously thought?

NARRATOR: The archaeologists are called back to the beach

to investigate a square shape

revealed by the impact of the tsunami,

similar to the one excavated at Saluvankuppam.

- The excavations reveal an 82ft long by 65ft wide rectangle

built entirely out of granite.

There's also an inscription in Tamil reading "cika malla eti"

engraved in the stone.

The terms "malla" and "eti" were titles used by Pallava kings.

RISKIN: Pallava refers to an old south Indian dynasty

that ruled much of this region from the 3rd to the 9th century.

They were incredibly powerful and had a huge influence

an the cultural and historical dynamics of India in that time.

- There is also a sculpture of a sitting lion

coated with lime and painted in the same style

we have seen in other Pallava temples.

But the way this lion is sculpted, sitting down,

indicates that it's from a specific period

of the 600-year rule of the Pallava -

the famous king, Narasimhavarman I, who ruled during the 7th century.

NARRATOR: Reports begin filtering through

that just before the tsunami hit,

when the water was sucked out to sea,

fishermen saw what they thought was a row of sculptures

on the ocean floor.

- The fishermen saw stone remains and what looked like big blocks

that made up a complex of sorts.

But then, as quickly as they appeared,

they vanished under an endless amount of water.

Could this be what remains of the actual seven pagodas?

NARRATOR: Diving underwater, archaeologists find a stone complex

that covers a significant area lying perpendicular to the shoreline.

- Similar to the temple that was found on the shore,

there is the foundation of a wall running for about 20ft

with shorter walls perpendicular to it.

They also find several large stone blocks scattered across a wide area

that appear to have formed a large structure that collapsed.

NARRATOR: This complex is constructed in a very similar way

to a famous ancient temple in Mahabalipuram, the Shore Temple.

They are both built using large granite blocks that are interlocking

without mortar binding them together.

- So, the construction styles are similar

and we know the Shore Temple is a site of worship.

So, could this complex under the water have had the same function?

- There are no remains of pottery at the bottom of the sea -

vital evidence that could indicate

that the space was used as a residence.

Nor are there any old anchors or maritime artefacts

that could indicate that it was part of the old seaport or harbour.

So, considering all this,

it's safe to say that it was definitely a site of worship.

This now underwater complex

may have been one of the Seven Pagodas.

- But what's weird is we know that, for the last 5,000 years,

there have only been minor fluctuations

in sea level all around here.

So, how did this place get so submerged?

NARRATOR: Archaeologists begin conducting analysis

of the layers of soil making up the coastline.

- The area has an average yearly coastal erosion rate

of around 1.8ft a year.

That's not very much but if you multiply it by 1300 years

which have passed since the Pallava dynasty happened

and since these temples were created,

that's more than 2,000ft of coastline eroded into the sea.

NARDI: So the complex was located well onshore back then.

The Pallava kings couldn't have foreseen

that the natural process of erosion

would one day put their magnificent temples under the ocean.

But what about the temple that was excavated on land?

It collapsed and was covered by sand. What explains that?

NARRATOR: Archaeologists begin looking at the sediments

surrounding the Saluvankuppam temple site.

The analysis reveals sand deposits

containing a large amount of single-celled organisms

with a relatively hard shell.

These are foraminiferans - or forams, for short -

tiny little organisms found throughout the earth's oceans.

They're basically like these cute, teeny-tiny amoebas with shells.

But what's important about their presence here

is that forams don't just end up on the beach willy-nilly.

- This foraminifera, found at the site,

doesn't live on the seafloor but drifts around the ocean

at depths of roughly 130-160ft.

If a storm destroyed these temples,

could that same storm have churned the sea up to such an extent

that they were transported from their habitat and deposited here?

- Although cyclones in this area are a serious force to be reckoned with,

waves only reach a maximum height of about 20ft,

which is not powerful enough to bring up organisms

inhabiting depths below 65ft.

- This means there must have been a really big wave

that churned the sea enough to bring those things onto shore,

something like a tsunami.

So, it's not outlandish to suggest that a tsunami or multiple tsunamis,

similar in size to the one from 2004,

destroyed the magnificent temples of Mahabalipuram.

NARRATOR: The destruction of the Pallava temples

and the subsequent loss of the Seven Pagodas

was the result of a series of natural disasters

and the inevitable impact of time.

Until now, the Seven Pagodas have been the stuff of legend,

only for a discovery made possible by disaster

to turn that myth into reality.

NARRATOR: On September 19th, 2017,

Mexico carried out an earthquake-preparedness drill

commemorating a devastating quake that struck on the same day in 1985.

Barely two hours later, the earth shook for a terrifying 20 seconds.

- This was known as the Puebla earthquake.

On the Mercalli scale, which measures the actual

real-world effects of a quake - it registered an 8 or "severe".

RISKIN: 370 people died.

More than 6,000 people were injured.

More than 150 churches were damaged or destroyed,

as well as several significant historical and cultural sites.

But here's the thing about that earthquake.

It was made way more traumatising

because it happened on exactly the same day of the year

as the infamous 1985 earthquake before it.

Sometimes coincidences happen but, for a lot of Mexicans,

it was hard to believe that this was just random chance.

NARRATOR: 35 miles south of Mexico City

and less than 60 miles from the epicentre

archaeologists in the town of Cuernavaca

are dismayed to discover serious structural damage

to the Aztec pyramid at Teopanzolco.

The Aztecs were a people indigenous to Mexico

that consisted of several ethnic subgroups

that spoke the same language and shared certain cultural traits.

They dominated Central Mexico from the 13th century

until the arrival of the Spanish in the 1500s.

- Teopanzolco is an extremely important Aztec site,

one of only a few surviving examples of the twin-temple design.

Its main structure, the pyramidal Great Platform,

is estimated to have been built around 1200,

and was active for a century or more before it was eventually abandoned.

AGBEDOR: The Pueblo quake put Teopanzolco's future in doubt.

Some of the most serious damage

was to the upper part of the platform within the twin temples.

The floors of both of them were dangerously destabilised and bent.

NARRATOR: Structural engineers and archaeologists, working together,

hurry to cut two wells, large vertical holes,

straight down into the corridor that's between the two temples.

- This was a kind of exploratory surgery.

They knew these temporary wells would further weaken the structure

for as long as they were open.

The plan was to get in, assess the damage, do the necessary repairs,

and get out as quickly as possible.

NARRATOR: But when archaeologists descend into the wells,

they come across something completely unexpected.

It's a structure, a rectangular box, about 20 by 13ft.

Its walls are covered in these elongated stone slabs

which were encased in stucco, an ancient sand-based cement plaster.

This is all inside the Great Platform. What on earth is this?

- Around 1200 CE, the Tlahuica,

a previously-nomadic Aztec subgroup,

moved into the Valley of Mexico and built Teopanzolco.

- Soon after they had built the Great Platform that we see today

and had started building the twin temples on top of it,

they suddenly, inexplicably abandoned the site.

Why? No-one knows.

- The design is made up of a pyramidal base

with a pair of steep staircases.

Atop the platform, there's a temple to Tlaloc, the god of rain,

and one to Huitzilopochtli,

the Aztec god of war and the sun.

NARRATOR: Hundreds of pottery shards are found

in and around the newly-discovered structure,

as well as one clearly identifiable artefact.

- This is a censer, a ceremonial incense burner.

The Aztec people believed that their four primordial gods

had been transformed into giant trees that upheld the stars.

They considered resin and sap to be the blood of trees,

so they collected and dried them to make sacred incense.

- A censer like this would have been used

to spread the smoke and aroma of the incense

throughout a space during ceremonies.

So the mere presence of it tells us that this concealed room

is a place of worship - a temple or a shrine.

RISKIN: Its design and shape are similar

to the temple Tlaloc directly above, even if there is a size difference.

So, based on all that, this was probably also a shrine to Tlaloc.

But why would it be hidden away down here?

NARRATOR: Experts in ancient Aztec building techniques

examine the physical interface between this hidden shrine

and the surrounding structure of the Great Platform.

- They determined that portions of the walls of the Great Platform

that surround this newly-discovered shrine

were connected to it or, in some cases, partially supported by it.

- This means that those outer walls

are newer than this inner, hidden shrine.

The shrine wasn't hidden at all when it was built.

It was built in plain view, was used for some time

and then, at some point,

the rest of the structure was built around and on top of it.

- This is exciting news because it means the entire site at Teopanzolco

is older than anyone had previously thought.

We had just been looking at the newest part of it

until the earthquake happened.

So how old is this place?

NARRATOR: The architectural characteristics

of the shrine's structure and analysis of the ceramic shards

date to around 1150 CE.

- The Aztecs believed that 52 years was one lifecycle -

for the gods and also on Earth.

So it was their practice that every 52 years

their religious buildings should be reborn.

They would build a new temple around and on top of an older one.

- The math works out perfectly. The buildings at Teopanzolco

were previously believed to go back as far as about 1200 CE

and this newly-discovered shrine

is estimated to be from around 1150 CE,

about 50 years older.

- So that would mean that the Tlahuica settled

and built a platform with the shrine by at least around 1150

and then, 52 years later, around the year 1200,

they built the larger Great Platform over and around it.

Then they started building the twin temples:

the one to Tlaloc and the other to Huitzilopochtli.

- Huitzilopochtli, the god of war and the sun, was significant.

The Aztecs considered themselves to be people of the sun

and believed Huitzilopochtli, as the sun god,

required nourishment in the form of human sacrifice

to maintain the strength to rise into the sky every day.

NARRATOR: Prior to the arrival of the Spanish,

the Aztec had begun documenting their history and cultural practices

in manuscripts now known as the Aztec codices.

Here they described many instances

of ritual human sacrifices being carried out at Templo Mayor,

which was the main temple of the Mexica people,

another Aztec subgroup in what is now Mexico City.

- It was common for the Mexica people at Templo Mayor

to drag a captured warrior, or whomever they chose,

up the steps by the hair, pin them down,

cut out their heart and burn it to send it to the gods as a gift.

- That was a major difference between the Mexica and the Tlahuica

according to the Tlahuica.

After the Spanish conquered the Aztecs in 1521,

Tlahuican informants told the Spanish

that the Tlahuica did not take part in human sacrifices

until the Mexica had conquered them

and forced them to do sacrifices

which would have been around the year 1430.

But was that true or is that just Tlahuican revisionist history?

NARRATOR: When Teopanzolco was originally unearthed in the 1920s,

archaeologists found no evidence of human sacrifice.

But during the 1960s, they unearthed a series

of seven curious stone platforms...

..five with sharp corners and edges and two that were rounded.

- One of those two round stone platforms had human skulls in it.

And it's known that the Aztecs used round altars

when making sacrifices to the god of the wind.

- They also discovered a pit of human bones -

the remains of 92 people,

of adults and children of both genders.

Also mixed in with the remains were ceramic offerings -

a flute and obsidian blades.

Obsidian, being volcanic glass,

naturally produces extremely sharp edges,

making it ideal for cutting into bodies, flaying skin

and scraping flesh off bones.

- So when the Tlahuica told the inquisitors

that they didn't practise human sacrifice

until the Mexica forced them to,

that might not have been the whole truth.

The discovery of these bones and the fact the artefacts buried with them

date from around 1300 CE

is positive proof that human sacrifices occurred at Teopanzolco

prior to it being abandoned.

- As for the older, inner shrine,

there's no hard evidence one way or the other

as to whether or not sacrifices were ever performed there.

NARRATOR: After carrying out the urgent refortification

of the Great Platform,

and taking as many recordings and samples as possible

in the short time they have,

archaeologists once again seal up all access to the inner shrine.

- Those wells had to be closed up.

Preserving the structural integrity

of a historical and cultural site like this

tops all other considerations.

- For whatever reason, when the Aztecs

built over the original shrine,

they purposely sealed off all access to it.

And it seems they planned their work very effectively

as it took a powerful earthquake to bring it to light,

even if only for a short time.

NARRATOR: The shrine and whatever other mysteries lie within it

are hidden once again.

For how long this time is anybody's guess.

NARRATOR: The Great Salt Lake, Utah.

A megadrought affecting the entire southwest of North America

means the largest lake west of the Mississippi is drying up.

- Since 2000, the water level of the Great Salt Lake

has been steadily decreasing.

There's less water flowing in

and, as temperatures rise,

much more is being lost through evaporation.

And because the lake is unusually shallow,

when the water level drops, the shoreline retreats rapidly.

- This is the largest saltwater lake in the Western Hemisphere,

so the name Great Salt Lake has been fitting,

but it's now a third of the size it was

when the first Europeans arrived here.

NARRATOR: On May 22, 2020,

a windstorm of uncommon power rose unexpectedly

and tore through the Great Salt Lake's southern shores.

- Windstorms in this area are rare, but they do happen

and they can appear suddenly with little to no warning.

And when those winds come through the mountains,

they can act like a funnel and accelerate airflow substantially.

AGBEDOR: The storm produced waves so powerful

that they damaged the lakebed and washed away quantities of sand.

And because the lake has a very shallow profile,

the shore gets unstable when it gets choppy.

NARRATOR: The day after the storm,

the state's park service was out assessing any potential damage,

when they made a remarkable discovery.

- Jutting up out of the water along the shoreline

are the ribs of a severely corroded ship.

It's between 30 and 40 feet long and the main structure is steel,

but there's some wood planking present.

So what ship is this?

- The Great Salt Lake is more than five times as salty as any ocean,

so all identifying markings on the vessel

have been eaten away by the lake's corrosive waters.

AGBEDOR: Most lakes ultimately have some sort of stream

or river outlet to the sea.

Not Great Salt Lake. It's what's called a terminal lake.

It sits on the Great Basin

which is like a big, shallow rock dish

that holds all the water in.

- Since the last ice age, as water has been flowing into this lake,

the only way any of that water has ever left the lake,

for the most part, is evaporation. Here's the thing with evaporation.

It's just the H2O that goes out. So all this salt and water comes in,

only water goes out and you just get more and more salt

and the salinity just keeps getting higher and higher and higher.

NARRATOR: Initial examination of the wreck site

reveals no artefacts or personal possessions

that can help identify it.

LEONARD: For millennia, of course,

it was only the native Americans who lived on the lake -

the Shoshone, the Fremont people and others.

It wasn't until the mid-1800s

that boats of European design made their first appearance here.

- The fact that this newly-discovered vessel

was primarily made of steel

immediately excludes many of the other ships

known to have sailed on the Great Salt Lake,

which were primarily made of wood - like the Cambria II,

a popular tourist vessel.

NARRATOR: Probing the wreck further,

something unusual about the ship catches the eye of observers.

- It has a flat bottom, unlike most vessels,

which have a V-shaped hull.

Because the Great Salt Lake has a shallow profile,

some working boats that had to carry heavy loads

were designed with a flat bottom to prevent grounding.

- Intriguingly, there's a rail line that cuts directly across the middle

of the Great Salt Lake and it's currently run by Union Pacific.

- Could it have something to do with this wreck?

NARRATOR: What's known as the Lucin Cutoff

lies about 50 miles north of the wreck site.

Now just a gravel-filled causeway,

the cutoff has a much more grand history.

- When the transcontinental railway was first built,

trains had to take the long, mountainous way around the lake,

between Lucin and Ogden.

That section of line was 146 miles long.

And going through the mountains

meant trains had to climb a steep grade, 700 feet up...

..only to go down again.

- After decades of having trains slogging through the mountain pass,

the Central Pacific Railway put an audacious plan into action.

They just kind of bypass right across the lake...

..including a section of wooden trestles that's 12 miles long.

- A trestle bridge design

is a large number of triangles all connected together.

This gives incredible strength and stability

enough that even a structure of wood can support a whole train.

But building one of these would take thousands of pieces of heavy timber.

And to get all of that wood out to the site

they use steel boats with flat hulls,

similar in size and design to the wreck.

NARRATOR: After the Lucin Cutoff was completed in 1904,

the supply boats weren't needed any more

and a lot of the fleet was sold off to various buyers.

- In 2014, one of the boats was found completely by accident.

And it happened when someone was using side-scan sonar

to search for a dropped piece of equipment.

That boat turned out to be the WE Marsh No.4,

which had been donated to the Sea Scouts in 1936

and was probably a sister boat to the wreck.

- We don't know exactly when or how this wreck met its demise,

but all signs point to it being a work boat

that's likely more than 125 years old.

And that played a vital role

in building an iconic American railroad trestle.

NARRATOR: The ship is a piece of history,

brought to light by a horrible drought and freak windstorm.

Ironically, a storm like the one that uncovered the wreck

may be what sank it in the first place.

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