All language subtitles for Historys.Greatest.Mysteries.S03E03.The.Dyatlov.Pass.Incident.720p.WEB.h264-KOMPOST (1)

Fishburne: Tonight, an infamous
Cold War cold case.

♪ ♪

Nine hikers found mutilated
on a remote mountain slope.

Their injuries and the facts
don't seem to add up.

- You can't help but wonder who
would be capable of doing this.

♪ ♪

- It looks like a murder scene

from a super graphic
horror movie.

Fishburne: Now, we uncover
the top theories

surrounding a place
that's been called

Russia's Area 51.

- There's a number of people
in Russia who believe

that a yeti is the culprit
in this case.

- This looks and feels a lot
like a coverup.

♪ ♪

Fishburne: Can new evidence

finally bring us closer
to the truth?

♪ ♪

- The bodies
all appear withered,

and some of them have
third-degree burns on them,

which is a sign
of radiation poisoning.

♪ ♪

Fishburne: What really
happened at Russia's notorious

Dyatlov Pass?

[dramatic music]

♪ ♪

The Soviet Union 1959.

As the Cold War between
the U.S. and USSR intensifies,

so do conspiracy theories
about covert experiments,

secret weapons, and spies.

And on February 26th, high up
in Siberia's Ural Mountains,

something equally nefarious
will be discovered.

On that day,
three cross-country skiers

spot a solitary tent
partially collapsed by snow.

- What was unusual was the
entrance was fastened closed,

but the outside
had been slashed open.

They looked inside, and they
found nobody was there,

but they did find
some footprints

leading down the hill.

- And when they get to the end
of that trail

they make a horrible discovery.

They find corpses in the snow.

Fishburne:
Warning: The images

you are about to see
are disturbing.

- Close your eyes and try
to picture the scene.

Imagine you're going
through the snow.

You come across these bodies.

It looks like a murder scene

from a super graphic
horror movie.

It just keeps getting worse
and worse.

- The first thing
the investigators found

were two members of the team

lying underneath a cedar tree,

and neither of them
were wearing winter clothes.

They were just
in their underwear.

One has burns
on his head and foot.

There's lots of cuts
and bruises on his body.

- He has some dried blood
on his face and also strange,

gray foam is found on his cheek.

- It looks like this
could be foul play.

The second body has
similar cuts and bruises.

He's missing the tip
of his nose,

and his knuckles are bruised
and swollen.

It's a very strange scene.

Fishburne: Several yards away,
another body.

- This third body is found
lying face-up in the snow.

He's hugging a branch.

He also has cuts
and bruises on his knuckles

and dried blood on his face,

and he's facing back
towards the tent,

suggesting he's trying to make
a desperate attempt to return.

- So naturally, the skiers
rush to report this,

and a bigger search party
is put together.

And this bigger search party
starts combing the area,

to try to find clues
as to what happened

to these three men.

But before they can
figure that out,

several more bodies turn up.

Fishburne: Next, they discover
a young woman.

- She has a lot of bruises
on her face,

and her hair is in disarray.

- She has this long, red bruise
on the side of her torso,

and on top of that,
her fists are clenched,

so it looks like maybe
there was some sort of scuffle.

Some sort of fight
that might have went down.

You also have to remember
this is Siberia.

You've got
freezing temperatures.

You've got blinding snow,
so all this work

that the search party
is trying to do,

to locate all of this evidence,
make the work

very, very slow and very,
very difficult to perform.

Fishburne: After a week,
a fifth corpse is found,

further up the slope.

- It's another
young male victim,

and this one has
a fractured skull.

Perhaps more evidence

that there was
some violent altercation.

What's interesting
about this victim

is he had one sock on one foot
and a felt boot on the other,

suggesting something took him
by surprise.

Fishburne: Six weeks later,
as the snow starts to melt,

the mystery deepens.

Members of the Mansi,
a local indigenous tribe,

approach the police
and lead them

to a makeshift snow shelter

250 feet from where the first
two bodies were found.

- The searchers--they start
to dig below the surface,

and they find this snow den

with these branches all lined up

next to each other forming
some type of floor.

Additionally,
they're also finding

some torn pieces of clothing.

There's a pair of sweatpants
with--[slicing]

The right leg
just cut off completely.

Likewise, there's also only the
left half of a woman's sweater,

so there's more
and more evidence

that's starting to build

that something violent
may have happened here.

Fishburne:
Investigators excavate

around the snow shelter,

revealing four more victims,

bringing the death toll to nine.

- These four bodies are lying
somewhat closely together,

in the bed of a rocky stream,
at the bottom of a ravine.

It looks like a dumping ground.

It looks like just someone
or something

may have dropped them there.

Fishburne:
Compared to the other victims,

these bodies have even
more ghastly injuries.

- One corpse is a male victim
with a severely twisted neck.

- Another young female
has a crushed ribcage,

and it's such a brutal injury

that her ribs
actually punctured her heart.

And horrifically, her eyes
and tongue are missing.

Another young male has
a massive fracture

to the side of his skull
that would have

almost certainly
knocked him unconscious.

- It looks more and more
like the injuries

are from brutal beatings
from some heavy, blunt object.

Fishburne: Investigators
soon identify the dead

as members
of an expedition sponsored

by the Ural
Polytechnic University.

They were reported missing

after failing
to complete their trip.

- Once you know
who these victims are,

it's even more tragic.

These students
were among the best

and the brightest from the
Ural Polytechnic University.

- They were very
experienced mountaineers

and well-respected members
of the sports club

of the Ural Polytechnic
Institute.

Fishburne: The group's leader
is 23-year-old

engineering student
Igor Dyatlov.

The tragedy bears his name.

- The Dyatlov Pass is named
in memory of Igor Dyatlov.

- He designed this expedition

to be
as challenging as possible,

so they could all get certified

as grade III outdoorsmen.

This was the highest category
in the Soviet Union

at the time.

Fishburne: In January,
the group leaves their home

of Yekaterinburg

and travels
to the village of Vizhay.

- From Vizhay, they go off grid

and head off
into the wilderness.

They have a compass and all
the gear they think they need,

but they don't have any radio
communication equipment

with them.

Fishburne: The trip
was supposed to cover

200 miles over 16 days,

but they only make it halfway.

- What frustrates friends
and family of these hikers

the most is that they say
that they are way too smart

and way too experienced
to have ended up

accidentally freezing to death
in the outdoors.

Fishburne: The lead
investigator in the case,

Lev Ivanov, says he knows
the cause of death.

♪ ♪

- There are signs of
a struggle at the scene,

and no one can ignore
the bruises

and cuts to the face,
and the body,

and the missing pieces of flesh.

Fishburne:
But who could be capable

of such a violent crime here?

The potential suspect list
is incredibly short.

- The mountain where the tent
was abandoned--

It's called Height 1079--

Is a mostly uninhabited area,

and it borders
the Siberian wilderness.

Almost nobody lives there.

Almost.

Except for the fact
that this region is home

to many of Stalin's
infamous gulags.

Stalin built lots of gulags.

If you don't know
what a gulag is,

it's this insane labor camp

where political prisoners
were sent.

They were forced to do hours
upon hours of manual labor.

This is where you have some of
the most hardened criminals

in the Soviet Union residing,

so investigators are thinking
maybe one of these prisoners

got out and encountered
those nine hikers.

Fishburne:
Especially when they learn

that the Ivdel Gulag
is only a few miles

from the site of the attack.

- Police check
with the Ivdel Gulag,

to see if there are
any prisoners that are missing,

but no,
they're all accounted for.

They also doubt any escaped
prisoners might have done this,

because no provisions
or belongings

were stolen from the tent,

so the escapee theory
doesn't go anywhere.

- So investigators
start to ask, "Okay.

It seems like
it's a very personal crime."

So they start to wonder,

"Could this have been
connected with anyone

that was affiliated
with that group?"

And one name pops up.

Fishburne:
The name? Yuri Yudin,

a tenth hiker with the group
and the sole survivor.

Is it possible that members
of the Dyatlov expedition

were killed by one of their own?

[percussive music]

♪ ♪

Fishburne: It's a mystery
that's gripped the world.

Nine Russian hikers dead
in a remote mountain pass.

Police are certain it's murder,

and among their top suspects
is fellow hiker Yuri Yudin.

- So Yuri Yudin is a
fourth-year engineering student

who was part of
that same group of hikers.

In fact, he's the tenth member
of that group.

But apparently,
Yudin left early,

and instead of ending up dead,
he's now the sole survivor.

Therefore, we can assume
one of two things.

Either Yudin
is incredibly lucky,

or he's the killer.

♪ ♪

Fishburne:
When Communist Party officials

question Yudin, he tells them

he backed out of the trek
long before the murders.

- Yudin claims to investigators

that his back started to hurt
when he was

making his way up the mountains,

which caused him
to quit the expedition.

He says that he left the group
on January 28th at 11:45 a.m.

at a location known
as the 2nd Northern,

and when he leaves,
the rest of his group

are all still very much alive.

Very much breathing.

But as investigators
are questioning Yudin,

they start to notice
he becomes a bit more panicked.

A bit more nervous.
They're certainly skeptical.

Fishburne:
Still unsure of Yudin's story,

investigators ask him to help
analyze the crime scene.

- And this has to be
traumatic for him.

Think about it.

He was supposed to be
on that expedition with them,

but because of his bad back,
he ends up going back.

And now, he's the only one
alive, of all of his friends.

So when he gets
to that crime scene

he acts with genuine shock
and surprise.

- Yuri notices something
the police couldn't have.

That some of the clothes found
on the bodies of those

in the ravine belonged
to some of the other students.

Fishburne:
It's another bizarre detail,

in a case full of them.

The clothing is sent
to a laboratory for analysis.

While they await results,

investigators tried
to verify Yudin's alibi.

- Yudin's story
of a bad back checks out.

Yudin was in his native village
of Yemel'yashevka

with his family on February 1st
and February 2nd.

The same dates
that investigators calculate

as the time of death.

Fishburne:
If Yudin's not the killer,

who else could be?

The only other known group
of people in the area

are the Mansi.

- The Mansi have helped
with the investigation.

And they're the ones that
pointed the investigators

to the four bodies
in the ravine.

Fishburne: Despite that,
Lev Ivanov

starts looking into the group.

♪ ♪

- So Ivanov thinks
that the Mansi are upset

that a group of outsiders
set up camp on Height 1079,

also known as Kholat Syakhl,

which roughly translates
to Dead Mountain.

- The explorers are violating
sacred Mansi territory,

and even more sacrilegious,

there are two women
in the group.

And for the Mansi,
women are forbidden to even

step foot on sacred land,
let alone look at it.

Maybe that's why the eyes
are removed

from a couple of corpses.

Fishburne: Ivanov interrogates
multiple tribe members.

While they deny involvement,
they offer a new detail.

- Several people tell the same
crazy-sounding story

that the Mansi saw lights
in the sky

or burning fireballs in the sky,

on the very night
that the hikers died.

Police recovered a camera
from the campsite,

and the last photo
on this camera

had an image
they didn't understand.

It looks like flares
or streaks in the night sky.

It's hard to tell,

but could this corroborate
the lights in the sky

that were supposedly
seen that night?

There are no timestamps
on the photo,

and if this is the last thing
the hikers photographed,

you can't help but wonder

if this has something
to do with the incident.

Fishburne:
Without a confession

or any evidence
that points to the Mansi,

Ivanov has no proof.

- So that's where things remain
for a while, at a standstill.

No new evidence,
and no new suspects.

Nothing to explain what
happened to the nine hikers.

Fishburne:
Until several weeks later,

when laboratory
results come back.

- And just when you thought
it was done,

here's a new chance
to find some new leads

and to keep investigators
moving forward.

The analysis of
the ripped clothing

that was found
in the ravine comes back,

and it reveals
an incredible new clue.

- The analysis shows
there's some unusually

high levels of radioactivity
on some of the items.

♪ ♪

Fishburne:
But how could clothes

from alleged murder victims
be radioactive?

The answer could turn the
course of the investigation

in an entirely new direction.

- But that's not what happens.

Instead of following
this new lead

and getting to the bottom
of the mystery,

authorities go ahead
and do the exact opposite.

On May 28, 1959, three months
into this investigation,

and after finding
this new evidence,

Lev Ivanov abruptly closes
the case unsolved.

The Soviet government seals
off the entire area

known as the Dyatlov Pass

and prohibits anyone
from going there.

Fishburne: Ivanov's report
marks a change.

He now states that
all nine deaths

were caused by an unknown
elemental force

which they were unable
to overcome.

But while Lev Ivanov
seems to want this

to be the final word,

it won't be.

Fishburne:
When nine hikers die

under mysterious circumstances
during the Dyatlov expedition,

the public is eager
to find out why.

But lead investigator Lev Ivanov

abruptly closes the case,
after three months,

just as he received
shocking evidence.

The victim's clothing
shows radioactivity.

- This is a crazy detail

that definitely deserves
some digging,

so as soon as a case
like this is shut down,

people immediately think
that it's a coverup.

Fishburne:
The question is why?

♪ ♪

- The USSR wants to be
the dominant superpower,

so they're doing a lot of
covert things at this time.

They're doing
research experiments.

They're doing
military experiments.

They have spy operations
going on.

Government coverups
are happening every day.

- The Soviet population
understands

that there are secret tests,

but also they accept
the rule of the government.

That this is secrecy
they cannot know about.

- I mean, it's not hard
for people

to put two and two together.

You got the Dyatlov deaths
and now the appearance

of unusually high levels
of radiation

on some of the clothes.

People are starting to think

that this is linked
to the military.

Fishburne:
At the victims' funerals,

friends and family remark

that the cadavers have an
unnaturally orange appearance.

- The bodies
all appear withered,

and some of them have
third-degree burns on them,

which is a sign
of radiation poisoning.

Fishburne: The family
of group leader Igor Dyatlov

say they are certain the
military was somehow involved.

But exactly what
are they covering up?

- Don't forget the Mansi said
that they saw fireballs

in the sky that night,

so one idea is that it's
a case of a weapons test

that goes wrong.

The rocket fails
to go into orbit and lands

really close to where
the Dyatlov hikers

are camped out for the night.

And it sends shockwaves,
which frightens them,

and it has them
running out of the tent.

- A different hypothesis.

Some think that it was
the Soviet government

or its military
that killed them,

because they witnessed something

they were not supposed
to have witnessed.

- And there's one
other little detail

that seems to prop up
this coverup theory.

It's presumed that one of the
hikers is actually a KGB spy,

and his name was
Semyon Zolotaryov.

♪ ♪

Fishburne: Zolotaryov is the
only person on the expedition

who is not a student.

In fact, he's 38 years old

and mysteriously
added to the group

by Communist officials
at the last minute.

- A lot of things about
Zolotaryov are a bit unusual.

For one, he's single,

which is kinda weird
in Russia at this time.

Additionally, he's got all
these very cryptic tattoos

on his body.

And at the start of the journey,

this older gentleman

tells the students to call him
by a fake name: Sasha.

- We do know that
Semyon Zolotaryov

is not who he pretends to be.

There's too much
in his biography

that is not consistent.

Even when he talks about
his service in World War II,

he mixes up dates when he
served in one unit or another.

And in my opinion,
having studied this case,

he was a top-notch
KGB operative.

- So the theory is that the KGB

is spying
on the Russian military,

to see what is going on
in these mountains.

And unfortunately, these hikers
just got caught in the middle

of an interagency conflict.

- So Zolotaryov is found out
to be a spy agent,

on behalf of the KGB.

So the group, although innocent,

are killed because of him.

Fishburne: When Zolotaryov's
body is recovered,

the film in his camera
has been destroyed

by water damage.

His motivation
and his potential KGB ties

remain a mystery.

- Whether the KGB was
connected to the case or not,

we don't know, but the idea of

the military being involved
in the whole mess

is very much popular

and one of the top hypotheses
in this Dyatlov Pass incident.

- Even the university,

the Ural Polytechnic Institute,

which sponsored the hike,
thinks this is what happened.

Fishburne: And in 1990,

another familiar voice joins
the chorus claiming a coverup.

- Lev Ivanov
published an article

with a strange title
"The Mystery of the Fireballs."

And he hinted that he was under
pressure to close the case

and not to continue to look
into the cause of the death.

- Communist Party officials
were incredibly worried

that these reports would
leak out to foreign nations,

and on top of that,
Ivanov believes

that it's these secret tests

that ultimately leads
to the deaths of these hikers.

Fishburne: Sole survivor
Yuri Yudin also believes

the government was involved

and reveals a key piece
of evidence

before his death in 2013.

- Yuri says that when he was
helping the investigators

with the inventory
of the items left

by the hikers,
things didn't add up.

He found things
that did not belong to anyone,

like a military cloth,
a pair of glasses,

also an extra pair of skis.

And his gut feeling
was that this was staged.

Fishburne: Even Boris Yeltsin
thinks authorities

are hiding something.

When he's made
President of Russia,

after the fall of the USSR,
in 1991,

he promises to investigate
the Dyatlov Pass incident.

- He was very much interested
in the case, as well,

because he was himself

a graduate
of the same institution,

Ural Polytechnic, and because
people appealed to him.

- He uses all of his
political power

to try to find information,

things that happened in 1959

that can shed light
on this event.

Now the closest
missile launch site

to the Dyatlov Pass

is actually located
in Kazakhstan,

and it's called
the Baikonur Cosmodrome.

Yeltsin's investigators dig
into the records of Baikonur,

to see if there were
any missile launches in 1959

during that window
of the hikers' death.

- He assured people that there
were no rockets during the day

when the hikers perished.

- It's tough to know if he
actually did look into this,

but if what he's saying is true,

there were no missile tests

that happened in the area
during that time.

- Whatever Yeltsin's
involvement with the case was,

it didn't bring us any closer
to finding the truth.

Fishburne:
Yeltsin's findings

seem to end the coverup theory,

but they don't stop the public
from asking questions.

And a shocking new one
is about to emerge.

[tense tone]

♪ ♪

Fishburne: After the fall of
the Berlin Wall in 1989,

the Dyatlov Pass case files
are finally made public,

giving amateur investigators
a fresh chance

to solve the mystery.

Digging deep into the evidence,

they find an intriguing photo
taken by one of the hikers,

and it leads
to a shocking new theory

and a surprising suspect.

♪ ♪

- There's a number of people
in Russia

who believe that yeti,

or snezhnyy chelovek,
in Russian,

is the culprit in this case.

In one of the photographs
found at the site,

there is a very unusual creature

that was detected
in the photograph,

and it's very interesting.

This was the last frame of the
photographs Nikolay Thibeaux

took at the site,

and I don't think
he had enough time

to think what he photographed,

but it's there,
historical evidence.

What you see in the picture
is a humanoid-like being.

It's big. It's about 10 feet.

It's hulking, much like
the yetis or snowman have,

and it looks like
it's looking at the group,

observing them.

♪ ♪

There were so many stories

coming from different parts
of the Soviet Union,

and this photograph could
definitely serve as a proof

that the yeti is out there.

The yetis are huge beings.

About 10 feet in size.

People are afraid of them,

because they could crush
with their arms and legs

a human being
and do it very quickly.

Fishburne:
Even the Dyatlov students

themselves make reference
to a yeti prior to their trip.

- Before they hike
into the mountains,

the students, the hikers

published a satirical newspaper.

And they write a headline
that reads:

"Latest evidence indicates
that the yeti lives

in the Northern Urals,
near Mount Otorten."

It's quite possible that

while they wanted
to express themselves

and show no fear by placing
jokes in that newspaper,

they knew that something
was out there,

and it could be yeti.

♪ ♪

Fishburne: Supporters
of the yeti theory

also point
to photos of the bodies

that show what appears to be
abject terror

with clenched fists
ready for a fight.

- Of course, seeing a horrible
creature like a yeti

by their tent, that
would have frightened them.

♪ ♪

Fishburne: But that's not
the only creature

that could get such a reaction.

- We have to account for many
predators that live in the area

that could have
attacked the hikers,

and among them are bears,
wild dogs, wolverines,

even the Siberian tiger.

- But the most likely culprit
in the animal attack theory

is a brown bear.

- The autopsy report listed
fractured skulls, broken chest,

scratches and cuts,
and even missing flesh.

A brown bear would be capable
of doing this,

but the problem
with the brown bear theory

is that they were in
hibernation around this time.

- That's all the more reason
if a bear wakes up early

and is hungry,
it would seek out nine campers

that just happen to be
in that area.

Fishburne: After decades
of public speculation

about animal attacks, homicide,

coverups, and much more,

in 2019, public fascination
with the Dyatlov case

prompts Russian authorities
to finally reopen the file.

A young prosecutor,
Andrei Kuryakov,

takes the lead.

- Andrei Kuryakov sits down
with a list of 75 theories.

Thanks to the growing
public interest,

this case has gotten
bigger and bigger.

Not sure if the yeti
has made the list,

but Kuryakov certainly
has his work cut out for him.

But it seems he's up
for the task.

Fishburne: As Kuryakov
starts researching,

he notices a detail
that leads to a new theory.

♪ ♪

- It turns out that the weather
on the 1st of February,

in 1959, is pretty extreme,
for that mountain,

with winds up to
65 miles an hour

and temperatures
down to 30 degrees.

And this has Kuryakov thinking,
"Could it be an avalanche?"

Fishburne: Andrei Kuryakov
organizes a 2020 expedition

to the Dyatlov Pass
to test his theory.

♪ ♪

And he's about to find
one key piece of evidence

that the original
investigation got wrong.

Fishburne: 60 years
after the Dyatlov tragedy,

prosecutor Andrei Kuryakov
returns to the crime scene

with new technology

hoping to prove the killer
was an avalanche.

- So they used photogrammetry
to really pinpoint

the location of the tent,

and then they take photos
of the current landscape

and compare 'em
with the old ones.

And they notice
a huge discrepancy

of what they
originally investigated.

- The location where the tent
was pitched in 1959

is actually several
hundred feet away

from where they originally
thought it was pitched.

- The location of the tent is
the #1 factor in determining

if an avalanche took place,

and it looks like
the original investigation

might have made a mistake.

♪ ♪

Fishburne: The risk
of an avalanche

depends on the degree
of incline.

On average, it takes
a 30-degree incline

to trigger one.

- Using the old incorrect data,

investigators prior to 2019,

thought that the slope above
the tent was about 15 degrees,

so they've ruled out
the avalanche theory

this entire time.

Fishburne:
The newly-calculated location

has a much steeper slope
of around 28 degrees.

- It's still not 30 degrees.

An avalanche still
may not be possible,

but with the right
weather conditions,

it's much more likely.

When they analyze the weather
conditions,

they find that there's
a special phenomena here

called katabatic winds.

Katabatic winds travel
at hurricane speeds.

In effect, they act
as a huge snowplow.

These winds can take tons
and tons of snow,

and it's very likely
that these winds could have

deposited huge amounts of snow
above the hikers' tent.

And that's when they become
even more confident

in their avalanche theory.

They think that this mountain
is a death trap

just waiting to spring.

♪ ♪

Fishburne: Once the weather
expedition is complete,

Andrei Kuryakov presents
his findings to the public.

- Kuryakov theorizes that
it's sometime after the tent

was set up around 7:00 p.m.,

a wind storm kicks off
into high gear.

- Sometime between
1:30 and 5:30 a.m.,

a small avalanche is triggered
above the tent

where they had cut
into the slope.

- That new snow up above
is too heavy,

and it crashes down
onto the tent.

After that initial snow dump,
the hikers,

fearing more is to come,

cut their own way
out of the tent

and run to a rocky ridge
150 feet away.

- This is, at the time,
standard avalanche protocol--

The idea of being able to find
a safe place

behind a high, rocky ridge

that would redirect
the snow away from them.

Fishburne:
But here, Kuryakov's theory

takes an interesting twist.

- He doesn't actually think
a bigger avalanche ever hit.

He thinks that
they hurried out of the tent,

but it never came.

And the problem is that
the hikers got disorientated,

and they couldn't find
their way back to the tent.

- So the investigator tests
his theory.

He blindfolds a man and a woman.

Makes 'em walk 90 feet away
from the tent,

and then challenges them
to find their way back,

and they can't.

Fishburne: And what about
their strange

lack of clothing?

- Kuryakov thinks
that some of them

were partially undressed
when they fled the tent,

but he thinks the others
may have suffered

from a phenomena called
paradoxical undressing.

And this is where people,

in their final stages
of hypothermia,

feel as if they're burning hot,

which leads them
to take their clothes off.

Fishburne:
According to Kuryakov,

sometime between
4:30 and 7:30 a.m.,

the hikers freeze to death.

- The two young men
found in their underwear

under the cedar tree died first.

The other members of the group

cut the clothes off
of their dead friends,

in a last-ditch effort
to survive.

At some point,
the group splits up,

and three of them--
Dyatlov, Kolmogorova,

and Slobodin--head back
towards the tent.

Sadly, they freeze to death
before making it back.

Fishburne: But what about
the final four?

- And this is where the theory
gets really weird.

You can never believe
this group had such bad luck.

The last four dig down
a snow shelter--

Basically a snow chamber

where they can hide
from the elements

and share body heat.

But the one spot
they decide to dig in

is above a stream through
a hollowed-out icy tunnel.

They dig down,
and the tunnel collapses.

They fall into the icy stream

and are buried under
15 feet of snow.

Fishburne: As he concludes
the press conference,

Kuryakov declares
that the Dyatlov Pass mystery

is finally solved.

- The Russians are outraged
at Kuryakov

and loudly reject his theory.

The families of the dead are
especially critical of him.

- Let's be clear. The public
hates the avalanche theory.

It doesn't account
for so many key facts

and details of the case.

- People were making fun of it
and disregarded it

because they know this is
another set of coverups.

Fishburne:
The Dyatlov Pass incident

has spawned
many theories over the years.

But in a case full of strange
details and unusual twists,

none have fully aligned
with the facts.

- You can say maybe
it's a bear attack,

but the bears are hibernating.

You say it's an avalanche,

but what about their clothes
testing positive for radiation?

What about the Mansi tribe's
testimony

of fireballs in the sky?

What about Semyon Zolotaryov,
the possible KGB agent

that was
planted among the hikers?

There are just so many details
to account for,

and there isn't just one theory
that makes total sense.

Fishburne:
But what if there is?

♪ ♪

- So theory after theory
after theory comes out,

and after a while,
people just stop

looking at all the evidence
one piece at a time,

and they just say
to themselves, "Well, what if

it's not just one thing?

What if all of these theories
are partially right?"

♪ ♪

So in other words,
it's an avalanche,

and it's a murder,
and it's a coverup,

and it's an animal attack,
all in one.

- If you start
with the fireballs

reported by Mansi
during the time,

it could be part of a nuclear
experiment we don't understand.

Maybe a new type
of nuclear weapons

that the KGB, of course,

did not want to leak out
to its enemies in the West,

and they covered it up.

Apart from Semyon Zolotaryov,

the others students--
Those poor students

did not know they were heading

into this special testing area.

This could explain
the radioactivity

that was found
in their clothing.

♪ ♪

Fishburne: A nuclear test may
also explain the avalanche.

- Those nuclear weapons
emit shockwaves.

Those shockwaves
are the catalyst

for the avalanche
to collapse on the tent,

and it could have caused
those blunt force injuries

on their own.

So in the span of an instant,

the explosion
startles the hikers.

It starts the avalanche.
It showers them in radiation.

The shockwaves hit them with
the force of a speeding truck,

which causes injuries,
and it causes them to rush

and escape
down the side of a mountain.

Fishburne:
From there, the coverup.

- If any of the hikers
would have survived,

the military could have
taken care of them,

because they didn't want
eyewitnesses to something

that is top secret.

- And even if they were dead,

the lead investigator,
Lev Ivanov,

was forced to close short
the investigation,

so nothing is leaked out.

- And finally,
the animal attack theory,

of course, accounts for injuries

that hikers had sustained,

because the animals
had access to the bodies

for a period of time,

and they did what animals do.

They ate into
the hikers' cadavers.

- What if it's a combination
of all of these things

that could have happened
to these nine hikers?

That's what
the Soviet authorities

are trying to cover up.

- No matter how the hikers
died, if there was a coverup,

their blood is on the hands
of the Soviet government.

The Dyatlov Pass incident
is the greatest mystery

and unsolved case in Russia,

but the government doesn't make

any more efforts to solve it.

So it is all up to us now,

amateur researchers
and investigators,

from all over the world,

to uncover what really happened.

♪ ♪

Fishburne: In 2020, the Dyatlov
Group Memorial Foundation

published a letter in support
of the all-in-one theory.

For the families
of the students killed

on the mountain that night,

that small vindication
will have to suffice, for now.

Because when it comes
to the truth of this mystery,

the secrets are buried
incredibly deep.

I'm Laurence Fishburne.

Thank you for watching
"History's Greatest Mysteries."