[narrator] An illustrious complex infiltrated
by a notorious gang.
It spiraled into a nationwide FBI investigation.
Become the city's most notorious gangster.
[narrator] A tranquil Japanese island
with a poisonous legacy.
[Rob] Doctors would perform surgery on the victims to examine
the biological effects in real time.
[narrator] And a top secret bunker
raided in the name of freedom.
[Geoffrey] If the Soviets had caught them doing this,
they would have put them up against the wall
and shot them.
[narrator] Near the famous Jersey Shore
is a derelict facility
tied to an extraordinary tale of corruption.
[mysterious music playing]
[Hadley] What is this place doing gathering weeds,
just 15 minutes away
from a glamorous destination like Atlantic City?
[Jim] It's got a tall brick tower,
a large grandstand,
and then this enormous overhanging roof.
[James] There are dozens of rows of stadium seats
overlooking an overgrown mess.
From the stands, you can barely see its full scale.
It all looks over this oval track
that is not really wide enough
to be a racetrack for car racing,
but clearly something went around here
at a high rate of speed.
[narrator] It was a spectacle that attracted
the rich and famous.
This became known as Hollywood by the Sea.
It also had a dark side,
it attracted criminal elements.
And what unfolded was something
straight out of a Scorsese film.
[Hadley] And soon, the FBI were closing its nets
on one of the most notorious
criminal gang leaders in the country.
[Jim] The investigation into the crimes
that were committed here
would ultimately lead to one of the biggest scandals
in US law enforcement history.
[eerie music playing]
[narrator] Maureen Bugdon worked here up until 2015.
Oh my God!
When I see the structure now
and how quickly it declined --
You remove the team, the staff, right?
It's as if you remove the heart.
[narrator] Maureen began as a model and assistant,
and over 20 years worked herself up to become president
of this exclusive club.
It was a facility designed in the 1940s
to scream glitz and glamour.
Atlantic City was one of the top
vacation destinations in America.
It had the famous boardwalk, hotels,
restaurants, entertainment.
[James] John B. Kelly Sr., an Olympic rower
and successful Philadelphia businessman,
was trying to capitalize on Atlantic City's popularity.
[narrator] Construction got underway in 1945.
A state-of-the-art clubhouse was erected,
surrounded by restaurants, bars, and a barbershop.
At its heart was the main draw,
a unique horse racing track.
[Jim] It was a mile and an eighth long,
a distance that the horse racing press soon started calling
a "smile and an eighth."
[narrator] It cost a massive $3.5 million,
the equivalent to nearly $60 million in today's money,
but high profile help was on hand.
[Jim] In the post war era,
horse racing was a very glamorous sport.
It attracted famous movie stars and celebrities.
It was written up in every newspaper.
[narrator] July 22, 1946.
The Atlantic City Race Course was ready for action.
It opened to a crowd of 25,000.
Among them were shareholders Frank Sinatra and Bob Hope.
Also in attendance that day was Kelly's young daughter.
She would soon become a name the whole world knew,
Grace Kelly.
[James] Nobody could have predicted the smash hit
this place was going to be.
[narrator] The opening day betting came in
at nearly $1.4 million,
recouping more than a third of the overall construction costs.
[Jim] Over the coming months and years,
this track would become a real magnet
for all kinds of celebrities and artists.
[James] There was Jerry Lewis,
Willie Mays,
and Sinatra's Rat Pack.
Even President Eisenhower stopped by for a visit in 1965.
[reporter] The nation's millions of racing fans are an interesting breed,
with a vigorous enthusiasm far surpassing
that of the followers of any other spectator sport.
[suspenseful music playing]
That's the jocks' building,
where the jockeys would get ready for the race.
That's the paddock walk ring
where the horses are paraded
before the race
and just underneath is, uh, saddling stalls
and a tunnel that runs right through the building
onto the racetrack surface itself.
[narrator] As the jockeys emerged from the tunnel,
the tension would build upstairs.
On a busy day with a hundred tellers,
you would have had lines about 10 deep.
It would be a flurry of activity.
[Hadley] Throughout history, gambling has always had
a dark underbelly, and this place was no exception.
[announcer] There up, way to a good start.
[Jim] By the early seventies, there was a guy
named Anthony Ciulla.
He was known as "Big Tony", in classic mobster parlance,
and he claims that he was able to fix races
in almost every state in the country.
[narrator] At the Atlantic City Race Course,
he could rely on support from the notorious Winter Hill Gang
and one of its leaders,
"Whitey" Bulger.
[Jim] This is a famous name to anyone who understands
the history of organized crime.
Whitey Bulger was this brutal crime lord in Boston.
He had rivals executed.
He was involved in all kinds of criminal enterprises.
[Hadley] Big Tony went about bribing jockeys and drugging horses
so that less favored horses would win,
and that would give him and his cronies a huge payout.
[Jim] Big Tony could offer these jockeys as much as $10,000
to throw a race.
And if the jockey resisted, he also had
the muscle of the mob behind him.
[James] On a grand July 4th race in 1975,
jockey Peter Fantini
was a little too obvious in holding back his horse.
[narrator] It would set in motion a chain of events
that would rock the racing world
and expose corruption
at the heart of the FBI.
2 [narrator] In 1975, jockey Peter Fantini
was caught holding back his horse
at the Atlantic City Race Course.
It would expose a race-fixing mobster known as "Big Tony."
[Jim] When Fantini threw that race, the feds got interested.
They pulled him in for questioning.
Pretty soon, he rolled over on Big Tony.
[James] Fantini admitted that Big Tony bribed him
to throw the race.
He even agreed to go to Big Tony's hotel
wearing a wire to implicate him.
[Hadley] So Big Tony was given a choice.
He could either snitch on his cohorts
or he could face a very long sentence.
His cooperation led to the conviction of over 40 people
and implicated over half of the jockeys
now in the Hall of Fame.
[narrator] His testimony included the infamous gangster,
Whitey Bulger,
and 20 other members of the Winter Hill Gang.
In 1979, they were nearly all sent to prison for race fixing.
But mysteriously, Bulger was soon back on the streets,
and now he was the top boss.
[Jim] Of all the people investigated
in this horse racing investigation,
Whitey Bulger was never indicted or prosecuted.
Why was he untouched?
[narrator] It turned out that Bulger was an FBI informant,
and he was being protected
by a corrupt agent named John Connolly.
[Jim] Bulger would tip Connolly off
about what various Boston mobsters were up to.
So he got rid of some of his competitors that way.
Meanwhile, John Connolly was tipping Whitey Bulger off
about what the FBI was up to
and who the other informants were.
A lot of those informants wound up
getting knocked off themselves.
[narrator] Connolly was later convicted for his role
in one of these murders.
He also tipped Bulger off when the FBI was finally
about to arrest him in 1994.
[Jim] Whitey Bulger escaped, went underground,
and he lived undercover for years.
[narrator] Meanwhile, the Atlantic City Race Course
began to see legal and cultural changes
eat away at its allure and popularity.
[Jim] As casino gambling was legalized in New Jersey
in the 1970s
and they started building
the big casinos in Atlantic City,
traffic to the racetrack began to drop off.
[narrator] It continued to operate for decades,
but was eventually abandoned in 2015.
The future of this legendary race course remains uncertain.
But the scandal that was sparked here in 1975
has left a damaging legacy.
Whitey Bulger went on to become
the FBI's public enemy number one
and was only captured in 2011.
In 2018, he was brutally beaten to death in prison.
[Jim] But the relationship between FBI agent John Connolly
and Whitey Bulger was a scandal
that the FBI took years to really own up to.
To this day, it's a stain on the reputation of the agency.
[narrator] In Lithuania, 15 miles from the capital Vilnius,
is a facility shrouded in secrecy.
[Katherine] We're in these dense, misty forests that really feel
like they're in the middle of nowhere.
[Dominic] If you were hoping to hide away from prying eyes,
this would be the perfect place.
[Katherine] And then, in this clearing,
there's what appears to be an office building,
but what's kind of strange is that there's this inner complex
with this big fence around it.
There's clearly more here than first meets the eye.
[Dominic] There's an entrance to something
buried in the hillside.
[narrator] Chosen for its isolation, this site was built
with one purpose in mind,
controlling a nation.
[Katherine] There's this really kind of strange mix here.
There's racks of electronics, but then there's kitchens
and a dining area.
[Geoffrey] It has all kinds of space for storage and for personnel,
but also one room after another
clearly fitted as a recording studio.
[narrator] This was the site of a daring raid,
right under the noses of the KGB's special forces.
[Katherine] If they were caught inside here,
they'd be put up against a wall and shot.
[narrator] It was part of a larger struggle that culminated
in a dramatic face-off that would shock the world.
They leveled their rifles at unarmed protesters
and plowed into the crowds in their tanks.
[narrator] Since 2008, Mindaugas Vanagas
has been researching this site,
trying to piece together the rumors
that swirl around it.
Many knew it only as "object number 523".
People who worked here told me that they were just told
to get to the bus and they would drive to some kind of place.
They didn't know where they are going.
Nobody knows about the place, where exactly it is.
[narrator] Built during the Soviet Union's occupation of Lithuania,
this complex was designed to be used in the fallout
from a nuclear strike.
[Mindaugas] This is decontamination zone.
When somebody gets into the bunker from outside,
he's washed and cleaned just to keep the contaminated materials
out of this bunker.
[Katherine] At the height of the Cold War, the arms race
between the United States and the Soviet Union
really made nuclear conflict a real possibility.
[narrator] Constructed between 1983 and 1985,
this is the Nemencine communications bunker,
part of a network that would enable the Soviet government
to take over the Lithuanian media
and control the information war.
This place was gonna be one of the critical nodes
where there would be a communication studio
to transmit to the people of the region what was going on
or what the regime wanted them to think was going on.
[Mindaugas] So that's the radio studio.
If you see, there's soundproofing walls all around,
the triple glass.
So one side was somebody sitting who's kind of speaking,
and the other side was guys who work with the sound.
[Dominic] Inside, there were television and radio studio facilities,
a full video and audio library, as well as offices
for the journalists and technicians.
[Geoffrey] Here, you had everything getting produced and recorded.
It would then send it along to another bunker,
which was linked to the television tower
in Vilnius, the capital of Lithuania.
[narrator] In the event of war, a staff of Lithuanians
would be rapidly replaced by KGB personnel
who would take control of the bunker.
But as the Soviet Empire began to crumble,
the threat of nuclear attack subsided,
and the people of Lithuania sensed an opportunity.
[Geoffrey] The Berlin Wall famously comes down
at the end of 1989,
and this triggers ferment all over the old Warsaw Pact,
as all the old subject nations of Russia start clamoring
for independence, declaring independence.
And this is what happens in Lithuania.
[Dominic] The country held multi-party elections
for the first time since 1940.
[narrator] Radio and television footage of these events
was beamed around the country.
The footage also included uprisings taking place
in other countries across the Soviet Union.
On January 11th, 1991,
the Soviets had finally had enough.
They launch a full-scale attack
to retake control of the country.
[narrator] Part of their strategy
was to cut the lines of communication
that were fueling the independence movement.
The bunker was now a priority target.
2 [narrator] In 1991, Soviet forces invaded Lithuania
to crush a growing independence movement.
The Nemencine communications bunker,
just outside the capital city, Vilnius,
was a top priority target.
[Dominic] The Soviets were desperate to sever
these lines of communication
that were allowing the opposition to organize.
[narrator] On January 11th,
heavily armed special forces
appeared out of the darkness and stormed the compound.
And these elite secret police units called OMON, O-M-O-N,
they go into the bunker to secure it,
to make sure the Lithuanians can't use its facilities.
[Dominic] Two days after having secured
this secret radio and television facility,
Soviet forces turned to
the capital's television building and tower.
[Katherine] This is where the events unfolding
across the country were being broadcast.
This is where people were getting their information
and understanding what was going on.
[narrator] The TV tower was broadcasting
footage of the invasion
and the Lithuanian independence movement.
Soviet forces arrived to take control of the narrative,
but found crowds of citizens had surrounded the buildings.
Ready to defend their freedoms at any cost,
it escalated into a deadly face-off.
[Geoffrey] The Soviets finally ran their tanks
into these human shields.
They kill 14 people and they wound more than 600
at the TV tower and other buildings around the city.
You can actually see footage of the Soviet soldiers breaking
into the studio and cutting the broadcaster's feed.
[speaking Lithuanian]
[narrator] With the bunker and tower now under Soviet control,
TVs and radios across the nation fell silent.
[Dominic] In the coming days, pro-independence journalists
and broadcasters scrambled to continue covering the story
by any means necessary.
[Mindaugas] Lithuanian people needed to know that
our government is still working and we are not gonna give up
and give everything to Russian soldiers.
[Dominic] Across the city, makeshift offices and studios
were set up, but there was a real shortage of
equipment needed to continue broadcasting.
[narrator] This closely guarded bunker
held that much-needed equipment.
There was one guy who kind of built this bunker.
He was looking after all the building site,
and he knew the bunker very well,
so he decided to help Lithuanian journalists.
[Katherine] One thing that the Soviet guards didn't know
was that there was a tunnel connecting the bunker
to apartments nearby.
[narrator] This man put his life on the line
and decided to sneak in past the guards.
[Mindaugas] So he used this long corridor,
and he was taking all the equipment,
silently, and bringing all that stuff
to Lithuanian journalists.
And obviously, if the Soviets had caught him doing this,
they would have put him up against the wall and shot him.
[narrator] The man's bravery paid off.
Journalists took this smuggled equipment and got to work.
Images of the independence movement
were shared around the world.
International pressure mounted, and after several more months,
the Soviets eventually backed down.
We take until September 1991 for the Soviet Union
to recognize Lithuanian independence.
With that, they withdrew their troops
from the capital and abandoned the bunker.
[Mindaugas] So the bunker was left without radio equipment,
and the cameras were stolen.
And after the Russian soldiers left, this bunker was left
without any purpose and use.
[eerie music playing]
Today, it's been put to a rather surprising new use.
[Katherine] The bunker is host to a sort of simulator of
what it was like to live under Soviet control.
[Dominic] It's a reminder that many of the freedoms we hold dear
are often more on a knife edge than we would like to believe.
[narrator] In Midtown, Detroit, two unusual structures
straddle an otherwise typical suburban street.
[Onyeka] They seem to be a sort of a conflation
of an industrial building
with something else more ornate.
[Alicia] One is low and almost fortress-like,
and the other is a mix of styles.
It's almost as if you sandwiched
a historic building in between two factories.
It's an intriguing mix.
[narrator] They may look different,
but they're very much connected.
Inside the oldest looking structure,
there's no mistaking what this was.
[Onyeka] As we enter, we see the stained glass windows,
the pews, but no parishioners.
And we see a stage and an altar, but no priest.
[narrator] This church and the surrounding complex
was more than a place of worship.
[Onyeka] This building did not only provide a foundation
for the civil rights movement, but many might argue that it
was here that the first speech around Black Power was given.
[narrator] It would also produce
some of Motown's most iconic performers.
[Alicia] It was a famous center of gospel music, and it gave rise
to one of the most successful vocal groups of all time.
2 [intriguing music playing]
[narrator] After the First World War, there was an influx
of white Southerners drawn to cities like Detroit
because of the high wages in the auto industry.
[Michele] In 1921, a Baptist church was formed in this building
to cater to some of those new Southern residents.
It was called Temple Baptist Church,
and it had an all-white, segregated congregation.
[narrator] But a bigger migration was already underway,
and when the church was put up for sale,
a cultural shift would send it in a new direction.
Motivated by the desire to escape racial violence
and pursue greater economic opportunity, there was
an exodus of Black Americans from the Jim Crow South.
[Michele] The need for industrial workers
in Detroit and other northern cities
drew millions of African Americans from the South.
It's part of what became known as the Great Migration.
In 1952, an all-Black church that was really trying to cater
to these Southern transplants decided to make
this place their home.
[narrator] It was transformed into
the King Solomon Baptist Church.
Current Reverend Charles Williams II knows all too well
the scale of the challenge they were taking on.
[Charles] When King Solomon, one of the first Black churches
on a major street in the city of Detroit,
purchased Temple Baptist Church,
which was originally a White separatist church,
they purchased 150,000 square feet.
That meant two buildings, one auditorium building
and one education building with recreation
as well as a sanctuary.
[Alicia] This was really more than a church.
It was really the heart of the community,
and it's where so many of the world's finest performers
graced the stage.
[Charles] So this facility served as an opportunity
and a place for gospel concerts.
Everybody played King Solomon.
If you were Lou Rogg,
Sam Cooke, who we all know and love,
played King Solomon.
And then, of course, we're strategically placed
right around the corner from Motown Museum.
[narrator] With its 5,000-seater auditorium, it became a regular
stop for artists hitting the so-called Chitlin' Circuit,
a collection of key venues they would play
on their tours across America.
This was one of the places on that Chitlin' Circuit
that all of the gospel artists wanted to play
because it was the largest facility
where you could have a real knockdown concert.
[Alicia] Berry Gordy, the founder of Motown Records,
was actually sitting here in the audience
when he heard three young, talented women do an audition.
And their names were Mary Wilson,
Florence Ballard,
and Diana Ross.
This audition ultimately landed them a deal
with Motown Records, but there was just one condition.
[narrator] Gordy insisted the group change their name,
and The Supremes were born.
The size of the church ensured that it served
not only as a community center,
but also a hub of political activism.
[Charles] Because of our classrooms across the street
in the auditorium right next door,
this became one of the convention centers for,
quite frankly, Black America.
And this put it right at the center of a rapidly
unfolding civil rights movement that was really
at a critical juncture.
[narrator] 1963 marked the centenary
of President Abraham Lincoln's Emancipation Proclamation,
ending legal slavery in America.
To mark the occasion, the church hosted
the Progressive National Baptist Convention,
and the keynote speaker was
Dr. Martin Luther King Jr.
His speech a week earlier,
during the March on Washington,
meant the eyes of the world were now on the church
where 10,000 people had gathered.
[Michele] Coming so soon after his "I Have a Dream" speech,
you can imagine the atmosphere. It must have been electric.
[Onyeka] This was a pivotal speech made at a time
when America was at the crossroads.
This place provided the foundation
for the next phase of that movement,
a movement towards direct action
and away from just the theorizing about equality.
[Alicia] Just a few weeks later, another speaker came here,
and he offered a stark alternative to MLK's vision.
[narrator] On November 10th, 1963,
Malcolm X delivered a seminal speech.
It would inspire many in the burgeoning
Black Power movement.
He was heavily critical of the nonviolent
civil rights movement that was put forward by the likes of MLK,
and he promoted revolution with violence, if necessary.
[narrator] But his fiery rhetoric didn't go down well
with everyone connected to the church.
Some ministers felt it might harm the civil rights cause.
So when he was scheduled to make another appearance
in April of the following year, the church actually tried
to prevent him from coming back.
[narrator] Since Malcolm X had already paid for
and advertised the speech,
he took the matter to court and prevailed.
When he arrived in April, 1964,
a presidential election was looming,
but many Black Americans were still being denied
their right to vote.
[Charles] We are in the balcony of a place where individuals
watched Malcolm X give the speech,
"Ballot or the Bullet."
[narrator] His message was clear.
If Black Americans were prevented from voting
in the upcoming election,
they should take up arms.
2 [narrator] In 1964, the King Solomon Baptist Church
in Detroit was a hub of civil rights activism.
With the presidential election just months away,
Malcolm X delivered a speech in the church's auditorium.
He declared that if Black Americans were denied
their right to vote, they were no longer willing
to turn the other cheek.
So 1964 was the year of "The Ballot or the Bullet."
[Onyeka] Malcolm's speech, "The Ballot or the Bullet",
was intended to light a fire under resistance.
He was saying that if the peaceful civil rights
movement doesn't work, then armed resistance
is going to be necessary.
And in this sense, his speech was extraordinarily
dangerous to the powers that be.
[three gunshot blasts]
[narrator] The following year, he was assassinated.
Speculation over who was behind the hit
has been rife ever since,
and in 2024, his family sued the CIA, FBI, and NYPD,
over their involvement in his murder.
In death, Malcolm X's teachings and speeches continued
to inspire a growing Black Power movement,
which was further fueled by the assassination
of Dr. King in 1968.
Riots swept through cities like Detroit,
which at this time was suffering economic decline,
driven by a collapsing motor industry.
[Michele] The city's population shrank by 60% between 1950 and 2010,
and the church's congregation shrank with it.
Eventually, they could no longer afford the bills,
and so they moved into the auditorium,
leaving the church building to decay.
[Charles] I'm honored, and I've never gotten used to the fact
that I stand in the same place where Malcolm stood,
where Doc King stood.
[narrator] The old church building remains closed,
but services and community work continue to take place
in the auditorium.
[Charles] As we're getting back to our roots,
we're utilizing the space for the community,
a place where
if you need a meal, you can get a meal.
We wanna continue on that legacy,
continue on that tradition,
and that's why the doors of the church
swing open today.
[narrator] On the Japanese coast, 43 miles from Hiroshima,
is an island famed for its nature.
[Lucienne] This island is one of 3,000 in this beautiful region,
and it really is tiny,
less than half a square mile in size.
[Sascha] The first thing you notice is rabbits.
They are everywhere. Where did they all come from?
[narrator] A closer examination reveals a number
of strange structures camouflaged in the rock.
At the top of the hill, we find this big stone expanse
sunken into the land, almost like an arena.
[Rob] Underneath, we see arched brick structures and domed rooms,
perhaps for storage.
[narrator] What was produced at this facility has left
a toxic legacy.
So for decades, no trees could grow here,
because of what was buried in the soil.
[Rob] What happened here was so secret,
the island was erased from the map.
[narrator] Local historian Naoto Shinmoto
first visited this site as a young boy.
[Naoto, through translator] I was in year six of primary school
the first time I came to Okunoshima.
As a local, I have complicated feelings about it.
[speaking Japanese]
[narrator] Like many who grew up nearby, Shinmoto was aware
that the island had an unsettling past.
[Naoto] It was a violation of international law,
so there was a strong gag order.
It had to be kept a secret.
This island was once a key part of Japan's defense.
[narrator] In the early 1900s, a rapidly modernizing Japan
began fortifying the region.
On this island, three gun batteries were constructed
as part of the Geiyo Fortress.
[Sascha] By the 1920s, the gun emplacements were outdated,
and the fortress was retired,
but the Japanese Imperial Army would find
a chilling new use for the island.
[narrator] They were inspired by technological developments
on the European battlefields during World War I.
April 22nd, 1915.
The German army releases clouds of poisonous chlorine
against British and Canadian soldiers
at the Second Battle of Ypres,
forcing the Allied troops from their trench positions.
[Sascha] And this was a new weapon, no one was prepared
for it, no one had gas masks, so it caused quite a panic.
[narrator] The physical effects of gas were excruciating,
but it also proved to be
a devastating psychological weapon.
[Sascha] Because of the horrific injuries
and indiscriminate nature of poison gas,
The Geneva Protocols of 1925
banned its deployment in warfare.
There are a lot of loopholes.
It didn't ban the development of the technology,
and it didn't ban the stockpiling of supplies either.
[narrator] A new Japanese leader would soon take advantage
of these loopholes.
[Rob] As Emperor Hirohito took the throne in 1926,
an increased focus on militarism
took hold of the country.
[narrator] The old Geiyo Fortress
was converted and expanded
for industrial scale production of a product
that would give the island its name.
This place was once known as "Poison Gas Island".
[Sascha] In choosing this island as the site
of a toxic gas factory,
the Japanese military was finding a careful balance
between a site remote enough that they could conceal it,
but close enough that they could get workers to it.
[narrator] Only a 15-minute commute from the mainland,
Okunoshima ticked all the boxes.
[Lucienne] Construction began in 1927,
and the factory started operating in 1929.
[Naoto] This building was to store poison gas.
100 tons was stored in each tank,
and there were six of them.
[Lucienne] It was soon producing a range of terrible poisons.
Mustard gas, chlorine, vomiting and sneezing agents,
and hydrogen cyanide.
[Naoto] The production and use of poison gas
was a violation of international law.
So, for that reason, it became a secret island.
It was erased from the maps.
[narrator] When Japan launched a full scale invasion of China
in 1937, they unleashed a reign of terror.
[Rob] Chinese troops were pounded with poison gas shells,
had no gas protective clothing,
and couldn't retaliate with gas of their own.
[Sascha] During the Battle of Shanghai, the Japanese attacked
the Chinese with gas 13 separate times.
[narrator] The Imperial Japanese Army quickly occupied
huge swaths of northwest China.
In Manchuria, the use of chemical weapons would reach
disturbing new heights
under the highly secretive program,
Unit 731.
2 [narrator] In the late 1930s, poison gas was being produced
at a factory on Okunoshima Island.
The Japanese army used it to brutal effect against both
soldiers and civilians during the invasion of China.
It was also utilized by a secretive unit masterminded
by the army's Surgeon General, Shiro Ishii.
[Sascha] Shiro Ishii was trying to develop new techniques
of chemical and bacteriological warfare.
The gas developed on Okunoshima was used
by the infamous unit Unit 731,
which was a group that conducted human experiments.
[Rob] Inside Unit 731, more than 3,000 Chinese prisoners of war
and civilians were subjected to disgusting experiments.
[narrator] Gas chambers were set up to test subjects
with blister agents and nerve gas.
Doctors would perform surgery on the victims to examine
the biological effects in real time.
[narrator] As the tide of war turned against Japan in 1943,
they faced an acute shortage of labor and materials.
Back on the island, they drafted in schoolgirls
to fill the gap.
Girls as young as 14 were made to produce poison gas.
After the Japanese surrendered in 1945,
they tried to hide the evidence by dumping the gas.
[narrator] Large quantities were quietly disposed of in China.
Most of the factory complex was demolished,
and its employees left to suffer alone
as the government tried to cover up the program.
And it's thought that nearly 7,000 factory workers
were left with lung disease, cancers,
and other debilitating conditions.
[Sascha] The use of chemical weapons wasn't even mentioned
in the Tokyo War Crimes Tribunals,
nor were the doctors who were part of Unit 731.
In the 1990s, the Japanese government was
finally forced to confront the terrible legacy
of its chemical weapons program.
[narrator] Leaks from the gas dumps in China
began causing injury and even deaths
among innocent civilians.
In the 2000s, Japan paid compensation to some
of the victims and built a facility to dispose
of abandoned mustard gas shells,
but many still live with long term conditions today.
As for the rabbits, their origin remains a mystery.
[Naoto] There were around 200 rabbits,
and they used those rabbits in the poison gas experiments.
But at the end of the war, they were disposed of.
So the records say that the rabbits of today
are different.
[narrator] Today, Okunoshima is a place
for people to come and enjoy nature.
But the island does not shy away from this dark chapter.
[Naoto] The fact we made poison gas needs to be known.
In that sense, I believe this island is important.
A museum was opened on the island to chart and educate
about its dark past.
[Naoto] Now it's called Rabbit Island,
and people come from all over the world
to enjoy its atmosphere.