Original subtitles

[announcer reading]

[wind whistling]

[narrator] The macabre discovery of a human skeleton

launches a murder investigation.

What are sheep's teeth doing inside a man's mouth?

This seems a lot darker than was initially thought.

[narrator] Fall out from a military plane crash

raises suspicions.

This site has some strange anomalies.

Did they lose control of the plane

and die in a fiery crash?

[explosion booms]

[narrator] The remains of a mysterious creature

emerges from the permafrost.

[Alison] At first, he thinks that it could be a dead reindeer,

but he quickly realizes

this is something he's never seen before.

What could it be?

[narrator] These are the strangest mysteries

trapped in the coldest places.

Lost relics.

Forgotten treasures.

Dark secrets.

Locked in their icy tombs for ages.

But now, as ice melts around the world,

their stories will finally be exposed.

[tense music plays]

[wind whistles]

[narrator] On the Swedish island of Oland,

the ruins of ancient stone forts rise up

above the frigid Baltic Sea.

The climate here can be absolutely brutal.

With bitter temperatures and the raw winds

coming in off the sea.

It can be a hard place to live at any time.

[Anthony] It's not just the weather that's intense,

the history of this place is also wrought with term.

The island has played a central role in the region's history.

And you can still see over a dozen ancient forts there

that predate the Vikings.

One of these forts is called Sandby borg,

and it dates from the 5th century.

[Anthony] This was the era just before the Vikings.

It was a dangerous time.

So, you can imagine that living in one of these

would have provided a greater measure of security for the people.

The fort is classified as what we now call a "ringfort."

Basically, it was a fortified settlement,

meaning entire communities lived behind the stone walls.

[narrator] In 2011, a group of archaeologists

from Linnaeus University

and the local Kalmar County Museum

are conducting a full-scale excavation

in order to find out what may lie below the soil.

Shortly after their work begins,

they discovered a human tooth and then a jawbone.

[Anthony] Then suddenly, two skeletal feet sticking up out of the soil

makes them realize that this is not gonna be your average dig.

[narrator] The initial excavation yields 26 skeletons

almost all intact.

Their bones exposed to the light for the first time

in over 1,000 years.

Twenty-six bodies. That's astonishing.

Especially considering the people lived here.

So, it's not a place where they wanna bury their dead.

So, what could have happened to them?

[suspenseful music plays]

[narrator] This fort was in use in the 5th Century,

around the same period as the Justinian plague was ravaging Europe.

This horrific disease killed up to 50 million people worldwide,

which was about half the global population at the time.

This part of Scandinavia was not spared the ravages of the disease.

If 2 to 300 people were living here all at once,

it's likely they're all packed together like sardines,

living in somewhat unsanitary conditions.

If it was densely populated and there was an outbreak,

conditions would have been right for a disease like the plague to spread.

So, could this be what killed them?

[narrator] Archaeologists working this site

discover more bodies lying in strange positions

on top of each other.

They find one skeleton of an adolescent

lying with his feet across the midsection

of another grown man.

In another area, the body of an elderly man

is found lying across the central hearth of a house.

His pelvis is charged but the rest of his body

has been spared the flames.

Because only part of his skeleton is burned,

it means that his soft tissue was present

and intact when he felt across the fire.

And he would have either been dead or unconscious when he did so.

[Anthony] If they died of disease,

they wouldn't have ended up like this.

Maybe they would have been found in their beds,

or maybe buried or properly cremated.

But these skeletons seem to be lying

in the same contorted positions they died in.

Some 1,500 years ago.

[Jamie] So, if it wasn't disease

that killed these poor people,

could it have been something else?

A battle perhaps.

[narrator] Archaeologists examine the skeletons,

looking for any signs of what might have happened to them.

[Alison] Some of their heads have been smashed with a blunt object,

while others show signs of sharp force trauma to their heads,

to their shoulders and to their hips.

[Anthony] What the archaeologists noticed

is that these wounds have all been efficiently distributed.

That means that the attackers have targeted the same place on their body

and done so to full effect.

[Jamie] The evidence of trauma

doesn't seem consistent with the fight.

Usually, if there's been a battle,

then you'd see fractures on people's arms

from trying to block the blows,

as well as more facial trauma than we see here.

[Alison] Also, some of the skeletons exhibit trauma

on their sides and backs,

meaning that some of them were likely attacked from behind.

This seems a lot darker than was initially thought.

[Amma] These archaeologists are quite literally standing

on top of an ancient murder site.

[narrator] Both the positions of the bodies

and the specific signs of trauma

point to this act being carried out

by a large group attacking simultaneously

and ensuring that none of the victims

could defend themselves.

So, if it wasn't a battle between two opponents,

maybe this tragedy was the result of a robbery.

[narrator] With a population of 2 to 300,

a fort this size would have contained a lot of valuables

such as gold and animals within its walls,

making it a target for marauding thieves.

Searching for clues,

the archaeologists make some astonishing finds.

They ordered five separate deposits of some exquisite,

gilded silver brooches.

[Alison] These were used as a means to fasten one's tunic

around the neckline,

but they could also be used to denote status.

[Amma] These brooches would have definitely been valuable.

So, if this was a robbery, it would have made no sense

to not steal them.

[Alison] The archaeologists also find

silver attachments for necklaces,

cowrie shells and glass beads.

Jewelry like this is something you would want to keep.

There were also plenty of bones from domestic animals

like sheep and dogs.

This doesn't really add up.

If it's a robbery, you take what is available.

And they didn't take valuable jewelry or animals. Why not?

[narrator] Looking at the massacre site of Sandby borg,

the archaeologists are struck by the fact

that not a single victim was ever buried

neither immediately nor long after the massacre.

[Alison] This is strange.

Why did no one ever bury these bodies? I mean ever.

No one touched this place after the massacre.

[narrator] The team considers the burial customs of the time.

Pre-Viking burials in the region were usually comprised

of bodies placed in stone and wood lined graves,

or in pits covered with stone slabs.

A proper burial would've been considered an essential right.

One that all men, women and children

would've needed in order to access the afterlife.

[Jamie] According to the beliefs of the time,

if a body remained unburied,

he or she would remain stranded in this world,

neither dead nor alive, with no place to go,

and no grave for their community to pay homage to.

Maybe this way, they're destroyed not only physically,

but perhaps more importantly, spiritually as well.

[narrator] As archaeologists pour over the bodies,

they make a peculiar discovery

in one of the skulls.

Inside the mouth of the old man who had fallen across

the fire they find teeth,

sheep's teeth, four of them.

[Jamie] What are sheep's teeth doing inside a man's mouth?

Someone must have placed them there. But why?

[narrator] Archaeologists on the Swedish island of Oland

uncovered the grisly remains of a 5th Century massacre

that left behind 26 skeletons.

After finding sheep's teeth deliberately placed

in the mouth of one of the skulls,

they consult the history books.

Looking for information about the burial practices of this time.

They come across something known as "Charon's obol,"

which was common practice at the time.

When people died, their relatives sometimes

placed a coin in their mouth, symbolizing the payment

that they would need to pay the ferryman

when crossing the river from the world of the living

into the world of the dead.

So, instead of coins to help the poor man cross over

to the afterlife, the killers placed sheep's teeth there.

This would be a sign of ultimate humiliation.

He would have gone like a beggar to the ferryman

with nothing to show for his life, but sheep's teeth.

For someone to do something like this,

they would really need to be filled with anger

or maybe desperate ambition.

[narrator] Puzzled by this question,

the team continues to dig

and discover a cache of beautiful gold coins.

But on closer inspection, they realized that these aren't just any gold coins.

They're what's known as "solidi."

Roman coins that are minted far away in the Roman Empire.

This is potentially a huge clue.

It means that this community, or more likely,

the entire island of Oland,

had a link with the Roman Empire.

[narrator] The Roman Empire at its peak stretched

from today's Spain to Syria,

as far south as the Nile River Valley

and on the European continent,

as far north as the Rhine River.

An empire that powerful would have had influence

even in areas which they didn't directly control.

[Alison] So, despite being outside the boundaries of the Roman Empire,

it's pretty much guaranteed that the people on the island

would have sought to develop relationships with Rome.

And these coins prove it.

It makes sense, because after all,

Rome was where most of Europe's riches

were concentrated at the time.

[narrator] Archaeologists conclude that the inhabitants of Sandby borg

as well as the rest of the island

were indeed reliant upon patronage networks

that linked to the Roman Empire.

The wealth flowing into Oland would have been vital

to the economic and political stability

of the different communities on the island.

But if that stability were disrupted,

say by the collapse of the Roman Empire,

well, that would be likely to have

far reaching consequences.

[narrator] While analyzing the coins,

an archaeologist notices something interesting.

Many of the Roman coins found at Sandby borg

are dated to the 460s.

But excavations on the eastern side of the island

have found coins minted in the 470s.

This means that Sandby borg had been receiving payments

that came to a sudden halt.

Based on the dates of these coins,

so when payments picked up again,

it appears that they went to the eastern side

of the island instead.

This all happened at a time leading up to the massacre,

meaning something had transpired

to spark this drastic shift.

The archaeologists conclude that the massacre

was likely the result of inter-island conflict.

Someone, maybe from the eastern side,

murdered all of these people

likely to seize or to maintain power.

[narrator] Access to this stream of Roman wealth

would have been highly coveted on the entire island.

This could have motivated the vicious attack

on Sandby borg by one of the rivaling neighbors.

It could be but as of now, we just don't know.

Archaeologists on the island

are still conducting excavations at Sandby borg and the rest of Oland.

However, one thing is certain, and that is the human beings.

Whether they live 1,500 years ago or today,

will go to extraordinary lengths

to acquire and maintain power.

[tense music plays]

[narrator] Home to over 300 volcanoes.

The Kamchatka Peninsula in eastern Russia

is known as the land of fire and ice.

The epic dome of the Mutnovskiy volcano

is one of the most active in the region.

The volcano is about 45 miles

from the Russian city of Petropavlovsk.

And the area is only for true adventurers

who can survive by their wits if the weather turns bad.

[narrator] In 2000,

researchers investigate an unusual site.

Scattered across a rocky volcanic slope

is the mangled remains of an airplane.

Upon inspection, the wreckage is a PV-1 Ventura

twin-engine, patrol bomber.

An airplane used by the United States Navy

in World War II.

[Anthony] The PV-1 was a long-range bomber

with a crew of seven.

It had a maximum speed similar to that of the Zero,

a Japanese fighter plane.

And it could carry up to six 500-pound bombs.

But the crash has researcher's puzzle.

There's something weird about the shape of the debris field.

It's not a typical crash site pattern.

And weirdest yet, the bodies of the crew are missing.

What is an American World War II aero plane

doing on a remote Russian coast?

[suspenseful music plays]

[Amma] On the tail fin,

researchers find the serial number

which allows them to match the plane

to U.S. Navy records.

The discover the plane was known as "Bomber 31."

[narrator] In the early days of World War II,

America took a pounding in the Pacific.

But by 1943 the tide had turned

with the U.S. having seized the initiative.

They attacked the Japanese positions

in the Aleutian Islands off Alaska

and took back the tiny island of Attu.

[Anthony] The U.S. quickly builds a naval base on the island,

which puts their bombers within reach

of Japan's northern territory islands.

[Morgan] But this was no easy task.

I mean, they were plenty of dangers.

Weather over the Bering Sea can be brutal to fly in.

Plus, there were 3,000 pounds overweight

carrying extra fuel for the long flights.

[narrator] On March 25th, 1944,

a seven-man crew in Bomber 31 took off from Attu.

They were headed for the Japanese islands

of Shumshu and Paramushiro.

The round trip will take nine hours in subzero temperatures.

The route is known as the "Empire Express,"

and it was so cold they greased their faces

to prevent them from getting frostbite.

[Jamie] They never returned.

But the mystery of what happened to the crew of Bomber 31

might still lie in the crash site.

[narrator] Researchers wonder if the plane

could have exploded in midair,

killing the crew aboard.

As they search the Bomber 31 crash site

for evidence of human remains,

they realize everything is not what it seems.

[Amma] There are several common debris field patterns

that air accidents can be grouped into.

This depends on the speed of the crash

and the angle of impact.

But this site has some strange anomalies.

[Morgan] An explosion in the air

would send debris falling down in a scatter pattern.

But when they start checking off key components

of the wreckage to map the site,

they find something really strange.

[Jamie] The Plexiglas has vanished

from the gunner's nest.

The 250 caliber machine guns are missing.

The cockpit instruments have been taken.

And five out of six bombs are gone.

[Amma] This can only mean one thing,

someone has been here before

and has removed these things from this area.

[Anthony] Nearby the wreckage there are three craters found

where it looks like someone detonated these bombs

at a later date.

And nearby that another live bomb is found.

[Jamie] We know this area was top secret during the 1960s

and completely off limits to civilians.

It's highly possible that the KGB came in here,

tampered with the site and cut up the fuselage.

[Anthony] The scattered debris pattern is not the result

of the plane having exploded in the sky.

This was the time when superpowers

were trying to spy on each other from the air.

So, maybe the KGB move things around to hide the fact

that this was an American crash site.

[narrator] Undeterred,

investigators focus their search on finding

any evidence of what happened to the men.

[Amma] There are large caliber holes

and heavy battle damage to both engines.

The damage is consistent with being shot at

by fighter planes.

[Jamie] But the angle of these holes are not

in the usual place you would see damage.

Fighter jets usually sit themselves

in the six o'clock position which is behind their target.

Then, they shoot.

These holes were made from above.

Judging by the location of the damage,

it looks like these men could've been injured

by the bullets or by the engine bursting into flames.

We just don't know for sure.

[Anthony] If the engines were disabled,

did they lose control of the plane

and die in a fiery crash?

[narrator] The wreckage of a World War II bomber

that vanished along with their crew in 1944

is discovered on the side of a volcano

on Russia's Kamchatka Peninsula.

But some strange anomalies at the site

leave investigators wondering not only how they crashed,

but what happened to the crew.

Careful inspection of the underside of the wreckage

reveals heavy scraping,

but there was no sign of a significant impact

on the ground or damage to the wings.

And strangely, the engines have been ripped

from their mouths and are lying halfway up the slope.

[Amma] They determined that the propellers

spun naturally to a halt.

This gives them a huge clue.

[narrator] Now they have a picture

of what might have happened to Bomber 31.

Near Shumshu Island,

they get attacked by Japanese fighters.

Tracers hit the engines and may have knocked them out.

They try to make Russia's Petropavlovsk airport

and allied territory.

Engine failure means they can't make it,

but they spot a fairly even slope on a nearby volcano.

They land the plane in deep snow on an uphill slope.

The touchdown rips the engines off,

and they land in one piece coming naturally to a halt.

[Jamie] But if the plane made a successful crash landing,

where are the crew?

Yes, some could have been injured or killed

before they landed, or even killed by the landing.

But one thing is for sure, someone landed the plane.

They had a good chance of surviving the crash.

And so that means if none of them had any life-threatening injuries,

some of them could've walked away.

[narrator] Unable to find obvious signs of the crew,

researchers go over the site with a fine-tooth comb.

[Amma] In the cockpit area, they discover a finger bone.

But this is such a strange thing to find on its own

when there are seven crew members.

[Jamie] About 300 yards north of the crash site,

they find a boot

bearing navigator Donald Lewallen's name.

But if he walked away from the crash,

he would've probably been wearing his boots.

[Morgan] Under a piece of the forward wing,

they discovered a fragment of human remains

in some cloth and some vertebrae.

Then, nearby they discovered two right collarbones.

[narrator] DNA testing confirms they are the remains

of only three men,

machinist, Clarence Fridley,

navigator, Donald Lewallen,

an ordinance man, James Palko.

The other four, pilot, Walter Whitman,

co-pilot, John Hanlon,

radio man, Samuel Crown,

and aerographer, Jack Parlier,

are still unaccounted for.

The radio was missing,

so they don't know if the crew could have called for help.

We do know the U.S. send six aircrafts

to search for several days after the plane disappeared.

But they found nothing.

[Anthony] It was in March of 1944

and the Kamchatka Peninsula may have had dense fog

or snow at that time of year,

which would have made it very difficult

to see anything.

And if the rescue party was also attacked,

it would have made for a very difficult search.

[Morgan] If any of the crew had life-threatening injuries,

it wouldn't have been easy to take care of them.

Especially in below freezing temperatures.

Exposure to the elements is a big factor in survival.

[Amma] Their rations would not have lasted them more

than a few days,

so they could have just slowly starved to death.

[narrator] When researchers expand their study

of the surroundings,

they discover evidence of a fire on a hill

that overlooks the crash site.

[Anthony] They find bullet casings in the charred ground

and think that maybe the crew set them on fire

as an attempt to send an SOS signal.

[narrator] But evidence of the KGB moving

some of the wreckage has some experts wondering

if the four missing men could have been taken prisoner.

A few days after they went missing,

there's a report of a U.S. airman

hearing the names of the Bomber 31 crew

reported as captured

on the Tokyo Rose propaganda broadcast.

A captured crew could be a highly valuable source

of top-secret information.

If they had been rescued by the Russians

or made the trek to Petropavlovsk,

they would have been taken prisoner or interned.

We do know that some U.S. airmen were imprisoned

in Soviet labor camps

and later executed

or forced to renounce their U.S. citizenship.

The lucky ones might have been interrogated

and then smuggled out of the country.

[narrator] But none of the Bomber 31 crew made it home.

The Russians played a central role

in defeating the access during World War II.

But despite being allied with the U.S.,

they entered some 22,000 American troops

over the course of the war.

Mostly as a result of having liberated them

from German POW camps.

While the vast majority of them

were repatriated back to the U.S.,

an unfortunate few were held as prisoners

by the Soviet Union, and some were even executed.

There's one theory above all others that strikes fear

in the hearts of many adventurers

who get lost or crash land in the wilderness.

[Morgan] The remains are so scamp and scattered

across this debris field that it could have been done by wild animals.

And there are definitely some menacing predators

roaming around on the Kamchatka peninsula.

I mean, bears, wolves...

In the 1940s, there were even Siberian tigers.

[Amma] Imagine facing a Siberian tiger

after being shot down over foreign territory

and surviving a crash landing.

I can't even begin to imagine the hardship.

[Jamie] If any of them were injured or dead,

the smell of blood would easily have been picked up

by local wildlife,

and they would have come to investigate.

[narrator] We don't know for sure,

but it is likely that the crew lost their lives

while trying to seek help after the crash.

The difficulties they would have encountered,

and the bravery required to face them are remarkable.

But this legacy endures is the story of Bomber 31

passes on into history.

[tense music plays]

[narrator] The Gulf of Bothnia, Western Finland

is known for its long, cold winters.

The land here is very flat,

and the marshy spring-fed fields

often freeze completely over during the winter.

[Jill] In the mid-1880s, a few miles from the coast,

farmers building drainage ditches

in a buggy field uncover an astonishing scene.

[Anthony] Buried in the mud, they find bones,

and multiple human remains

submerged in their lush fields.

[narrator] Over the next century,

multiple teams of archaeologists

investigate the site known as Levanluhta.

All together hundreds of broken pieces of bones

and multiple skulls were eventually found

scattered and mixed together in the soft, muddy soil.

After through search, a total of 153 pounds

of human bones were recovered from the field.

Researchers painstakingly count and analyze the bones

piecing fragments together,

and they determined that the field contains

the remains of at least 98 different individuals.

How could these people end up buried in the mud

in a farmer's field?

[wind whistles]

[Jill] This area has been farmland for centuries.

There are no grave markers or memorials

that give any indication of who they are.

And the locals have no knowledge of a cemetery nearby.

Whoever these people are, they've been here a long time.

[narrator] Carbon dating on the bones reveals they date

sometime between the 4th and 9th centuries.

[Morgan] So, these people are from the early Iron Age.

They predate the Vikings.

Could this be the remains of an ancient cemetery?

[wind whistles]

[narrator] Archaeologists in western Finland

uncover the remains of nearly 100 people.

Their bones are revealed to be centuries old

and predate the Vikings in this area.

Could they be evidence of an ancient cemetery?

[Jill] Other early Iron Age cemetery sites in Finland

show that at the time, bodies were primarily cremated.

So, finding the bones of this many bodies

from that period is highly unusual.

[Alison] The bones are scattered and mixed together

and don't appear to be laid out in an ordered way

like you'd expect if this was a cemetery.

[Anthony] When bones are found scattered like this at a site,

sometimes it's determined to be the remains of a battle.

The bodies lie where the soldiers fall,

and over time, they get mixed together.

[Morgan] But if this was the site of a battle,

and these were our fallen heroes,

then, where are all the weapons?

I mean, there's no armor, there are no buckles.

There are very few artifacts here other than bones.

[narrator] Five metal broaches and ten decorative arm rings

had been found in the mud at the site.

Not exactly the cache of weapons you'd expect to find

if this was the site of a battle.

[Jill] The armbands are all made in styles

that were popular from the 5th to 8th centuries.

So, it's possible that these people didn't all die at once,

and that they were placed there intentionally

over a span of many years.

[narrator] In some ancient Nordic cultures,

boggy and marshy areas were considered scary

and mystical places.

Bogs were used as places to sacrifice people

to appease the gods, or to bury someone

as a form of demeaning punishment.

They were thought to be the gateway to a dark afterworld.

The idea was that the dark spirits

would torment the deceased as a punishment.

Many individual well preserved bodies have been found in bogs

across England, Denmark, and many areas of Northern Europe.

[narrator] The chemicals from the peat moss

and the lack of oxygen in most bogs,

prevent bacterial decay in organic matter

and preserve the bodies perfectly.

[Anthony] It's incredible.

We can see every minute detail of these people's faces

and every injury revealing how they died,

whether it's by slit throat,

or by a blow to the head from behind.

But in this site, only the bones remain.

[Alison] So, perhaps Levanluhta was a place

where people in the community were buried or sacrificed.

The population in the area at that time

wouldn't have been that large.

So, 98 would have been a considerable number of people

to be sacrificed or punished for wrongdoing.

Even over a period of many years.

[narrator] The archaeologist noticed that the deceased

show no signs of trauma or head injuries

that would indicate they were killed or injured on purpose.

And while studying the bones and skulls further,

they make a startling discovery.

[Anthony] The length of the femur bones

and the shape of the pelvis

suggest what age and gender the deceased are.

And of the 98 bodies,

they determine that only a small percentage are men.

[Alison] The bones here are predominantly

those of women and children.

It's really unusual to find a site like this.

Separating the women and children is intentional.

It wouldn't have just happened randomly.

[Morgan] If the bodies were brought to the site intentionally,

then why are the bones all jumbled up?

I mean, it's almost like they just dumped them on top of each other.

[narrator] Biologists look at samples of the muddy soil

and discovered that it contains

interesting plant remains.

White lilies and other plants that live in water

were present at the time

some of the bodies were placed here.

So, it's possible that during the Iron Age,

this area wouldn't have been a marshy field,

but actually a lake or a large pond.

It's likely that the water's freezing and thawing cycle

moved and mix the bones around

over hundreds of years.

But if it was a lake,

why would they choose to bury their dead in it?

[narrator] Archaeologists see a number

of large wooden poles

made of birch wood planted vertically like flag poles.

The poles were found amongst the bones,

and they were clearly placed there in the earth

in a very specific manner.

But why?

[Jill] If this was a lake, and you're trying to keep

a body underwater, you'd need something to hold it down.

[Anthony] There is evidence of trees and branches

being used to weigh the bodies down in the water.

So, perhaps the same thing is going on here.

[narrator] Researchers determined that in Levanluhta

multiple poles were used to hold the bodies down

under the water.

Whoever did this was going to great lengths

to keep the dead submerged.

The archaeologists suggest this place wasn't a site

for unceremonious bog burials

but was instead a unique graveyard

for women and children.

[Morgan] This tradition is like nothing else found

in that area during that time period.

So, who were the people with such complex

and unusual burial practices?

[tense music plays]

[narrator] In a marshy spring-fed field

in western Finland,

archeologists discovered the remains of nearly 100 people,

mostly women and children.

They wonder if there was a sinister reason

for this underwater entombment.

Or was it just a unique burial practice?

DNA analysis of bones reveals the background

of some of the people whose remains were found.

They appear to be most closely related to the Sami,

the indigenous people from Northern Scandinavia.

[Alison] This is fascinating.

It means that the Sami, who today live mostly

in the north of Scandinavia

have been living much further south 1,500 years ago.

[narrator] The Sami have a belief

that some spring-fed lakes

are sacred places called "saiva."

These magical lakes have a double bottom

and underneath access through the water

is an identical upside-down lake

in the world of the spirits.

[Jill] The field of Levanluhta is currently drier,

but there are a number of springs in the area

that create the marshy conditions.

So, it's entirely possible

that this was a spring-fed lake at one time.

[Anthony] Saiva were thought to be the homes

of the spirits and the dead.

So, sacrificial offerings were made to the water.

So, as these people were related to the Sami,

perhaps these unusual water burials

were carried out for religious or ritual purposes.

[narrator] Researchers continue to investigate

the site and the bones testing their DNA,

hoping there may still be answers

buried in the frozen marsh.

[suspenseful music playing]

[narrator] In May 2007, in Russia's Yamal Peninsula,

a Nenets reindeer herder walks alongside

the thawing Yuribey River.

An unusual scene catches his attention.

Parts of a frozen animal are stuck in the permafrost

and arising out of a damp snow.

[Alison] At first, he thinks that it could be a dead reindeer,

and he approaches the remains to get a better look.

But he quickly realizes this is something he's never seen before.

What could it be?

[narrator] The creature is removed from the permafrost,

and its remains were taken to a lab

for deeper analysis to confirm what species

it actually is.

The frozen ground has mummified

this creature incredibly well.

That includes a treasure trove of DNA

that is very useable.

[narrator] Analysis of its well-preserved DNA

reveals that the animal is a baby mammoth.

The DNA sample is so strong scientists can even tell

it belong to a distinct population

of the species called Mammuthus primigenius.

[Alison] Mammoths roamed the northern hemisphere for millions of years.

But what's shocking about this discovery

is just how well preserved this baby mammoth is.

[narrator] Other than some damage to her right ear and tail,

the flesh, the muscles, the internal organs,

the milk tusks, and teeth are all untouched.

[Morgan] Even the eyelashes are intact.

This baby mammoth calf

looks like it just drifted off to sleep

and never woke up.

[narrator] Radiocarbon dating reveals

that this baby mammoth died some 40,000 years ago.

[mammoth yowls]

This was a time when humans and mammoths

coexisted in Siberia.

To survive the long winter months,

mammoths became the prime target

for Paleolithic hunters.

[Alison] They would gather in groups

and use their long spears to attack and kill them.

[Jill] But there are no wounds of any kind

on this mammoth's body.

This suggests it wasn't killed by Stone Age hunters.

There's no evidence of human interference at all.

So, what happened to it?

[narrator] After performing DNA analysis,

Russian researchers identify the calf as female

and call her Lyuba,

after the wife of the reindeer herder who discovered her.

To learn more about this miraculous baby mammoth,

the scientists began an autopsy.

By studying her premolars and milk tusks,

they learned that she was born in the late spring.

She was only one month old when she died.

[tense music plays]

[Kim] She was an infant.

Completely dependent on her mother for survival.

And like most mammals,

her mother would have done anything to protect her baby.

Did she become separated from her mother and starve to death?

[narrator] The pristine remains of an infant woolly mammoth

found in the Siberian permafrost

raises questions about how she died.

The scientists examined Lyuba's 40,000-year-old stomach and intestine.

They find traces of her mother's milk.

The discovery of fresh milk in her stomach

means Lyuba didn't die of starvation.

[Morgan] But milk is the least strange substance

found in this baby mammoth's stomach.

Researchers also found poop.

[Alison] Specifically, its adult mammoth feces,

and quite likely to be Lyuba's mother's.

Interestingly, this is actually behavior

that we see in elephants today.

[narrator] Modern-day elephant calves eat their mother's feces

to inoculate their guts with their microbes

in preparation for digesting plants as they grow.

[Alison] From this mummified baby,

the researchers are getting a vivid image

of how mammoths lived 40,000 years ago.

It's astonishing.

[narrator] The researchers continue to examine Lyuba.

Determined to uncover as much detail as possible.

They examine a hump of fat on the back of her neck.

Using an electric drill,

they take a sample for further analysis.

[Morgan] The scientists believe that the fat

is actually brown fat, which is a great store of energy

similar to a camel's hump.

This fat would have helped keep the infant mammoth warm

in the freezing Arctic.

Some researchers even believe it would have allowed mammoths

to be born earlier in the spring,

allowing them to be in better condition

to survive their first brutal Arctic winter.

[narrator] For general appearance and the healthy

hump of fat on the back of her neck

suggests Lyuba was in excellent health

at the time of her death.

If she didn't die of starvation,

perhaps she died from a disease?

[Jill] Another baby mammoth had been excavated

around the same time as Lyuba in northeastern Russia.

Scientists suspected that mammoth possibly died

from an anthrax infection.

It's possible Lyuba met a similar fate.

[narrator] Anthrax bacteria

are known to have infected animals on the tundra

going back hundreds of thousands of years.

The scientists know that with an anthrax infection,

sores or lesions can appear on the bodies

of infected animals.

[Alison] But Lyuba doesn't have any lesions like that at all.

In fact, her appearance for full stomach and back fat hump

indicates she was as healthy as she could be.

So, what killed Lyuba?

[narrator] Puzzled by the possible cause

of Lyuba's death, scientists performed CT scans on her.

With a 3D model of her body,

researchers could see Lyuba's internal anatomy

without cutting her apart.

The scans revealed something extraordinary.

Parts of her trunk and trachea were filled with sediment.

It seems like she inhaled a great deal of mud.

[narrator] Researchers extract minerals

from the inhaled sediment

and conclude that it came from a cold,

oxygen-deprived environment, like a riverbed.

[Morgan] Now we're getting a pretty graphic idea

of what probably killed Lyuba.

She probably drowned.

And in the process, she panicked

inhaling a bunch of water and mud.

[Alison] But there's still one lingering question

the scientists want answered.

Lyuba's body is so well preserved,

it really looks like she just drowned yesterday.

It's incredible.

But how is her body in such good condition?

[narrator] Scientists reason that after Lyuba drowned,

the sediment heavy river or swamp froze around her.

[Kim] And that's a stable,

physical chemical environments

in which oxygen is deprived.

And the bacterial process that normally degrades

organic tissue are slowed to a complete pause.

[Morgan] But again, that's relatively common.

And something unique happened to Lyuba.

So, what was it?

[narrator] The scientists take another look

at the evidence collected so far.

Something about the thawing mammoth

had caught their attention.

A slightly sour smell as it warmed.

It reminds them of microbes called lactobacilli,

which produce lactic acid

from the fermentation of carbohydrates.

So, in the sediment, there was this additional

acidic material which surrounded Lyuba

and preserved her after she died.

That pickling effect prevented her body

and everything inside it

from degrading for over 40,000 years.

[Alison] So, the remarkable preservation of Lyuba

is owed to a quirk of geography and timing.

The freezing water and the mud she drowned in

was rich in a very specific chemical.

And thanks to that, we can see that mammoths

and today's modern elephant have similarities

that go way beyond just their looks.