History's Greatest Mysteries (2020) s05e10 Episode Script

The Hindenburg Disaster

Tonight, a historic
catastrophe captured on film.
It's burst into flames.
Oh, my!
Oh, the humanity!
Of the 97 people on
board the Hindenburg,
13 passengers, 22 crew,
and one ground crew person
all perished in this event.
The Hindenburg Disaster,
in many ways, it was
the first viral video.
For decades, experts believed
they knew what
caused the disaster,
that leaking hydrogen ignited,
causing the airship
to burst into flames.
But there may be
more to this story.
Eyewitness testimony says that
they saw orange and red flames,
but hydrogen, when it burns,
it burns a light blue.
Some people on the ground
report having heard popping
inside the aircraft
during that last turn,
like something inside
of it went wrong.
Now, we'll explore
the top theories
behind this historic tragedy.
Basically, the Hindenburg
is flying with bandages on.
He gets actual fabric
from the Hindenburg,
and poof.
It goes up in flames.
What really caused
the Hindenburg Disaster?
Germany, May 3rd, 1937.
The world's largest
aircraft, the Hindenburg,
prepares to depart
for New Jersey.
The airship's tanks are full
of hydrogen and nitrogen,
fueling its 11th
transatlantic flight
to the United States.
The Hindenburg is
a derigable aircraft
that's filled with gas and
that makes it lighter than air,
so it can basically float.
Hindenburg provided something
that no other type of
aircraft could provide.
Three day passage from
Europe to the United States
in great luxury.
At 7:16pm,
the Hindenberg takes off
for Lake Hurst, New Jersey.
More than 10 stories tall,
stretching 804 feet long,
the Hindenburg is roughly
the same size as the Titanic.
Unlike a hot air balloon,
the Hindenburg is
a rigid airship
constructed with a metal frame.
It's filled with 16
cells of hydrogen gas,
which is a gas that's
lighter than air,
which makes it buoyant.
It floats without
needing to be lifted up
by any sort of wings.
The ship has a
triangular structure
through the very center
that runs all the way.
That's actually what the
crew would walk across.
And around that are
these metal frameworks
like the ribs of a barrel,
and outside of that
is an outer coverage,
seven acres of
aeronautical cloth
that has been painted
and carefully sealed
so that it is both waterproof
but also sturdy
from the elements.
Aluminum powder in the varnish
is what gave the Hindenburg
its silver color,
but it also served the purpose
of reflecting the sunlight
so that the hydrogen
gas did not get heated,
inflate, and burst.
Beyond its
technical achievements,
the Hindenburg is a
floating representative
of a sinister government.
The swastikas
emblazoned on the tail
were the national flag
of Germany at the time.
So basically, the Hindenburg
served as a flying billboard
for the Nazi
government in Germany.
Heil! Sieg Heil!
Thanks to recent upgrades,
the Hindenburg now
carries 72 passengers
and almost as many crew.
A one-way ticket costs roughly
$8,500 in today's money.
The Hindenburg was set
up for luxurious travel.
There were two decks
that included a
dining room, washrooms,
a full electric kitchen,
and even a smoking lounge.
They also had a grand piano
that had been
constructed of aluminum
and covered in pigskin.
For the most part,
the Hindenburg would
travel about 650 feet
above land or sea.
Captains were very conscious
of the passenger experience
and they would actually
lower the altitude
to allow them to
see amazing sights
that no one in
humanity ever had,
like icebergs from
above, floating by.
After a four year
long construction process,
work on the Hindenburg
is completed in 1936,
and that spring, it begins its
first international flights
to the United States and Brazil.
It was spectacularly
successful in 1936.
It went back and forth
across the Atlantic,
both the North Atlantic
and the South Atlantic,
and so they entered
the 1937 season
with so much pressure
on them to make this
first North American
flight of 1937 a success.
On May 6th, 1937,
after a nearly
three day journey,
the Hindenburg
reaches American soil.
As the Hindenburg is
heading for its destination,
Lakehurst, New Jersey,
there are storms ahead of it,
and so the Hindenburg can't
land when it's supposed to.
It spends hours waiting
for the storms to clear up,
and there are film
crews and radio crews
waiting to see this
amazing sight.
What the ship is supposed to do
is approach a structure
known as a mooring mast,
and once there, drop
the landing ropes.
At that point, the
ship drops its ballast
and then a crew of
about 200 burly men
grab a hold of those ropes,
attach them the winches,
and then start bringing
it down to the ground.
Then at
7:25pm, disaster strikes.
As the ship is landing,
the tail is getting closer
and closer to the ground
and they try to release hydrogen
in an effort to bring that
ship back into level.
Unfortunately, it's
just not working.
The tail continues to
fall below the bow.
And then suddenly,
an explosion occurs.
Oh, my!
It's burst into flames.
400, 500 feet into the sky.
This is terrible.
This is the worst of the worst
catastrophes in the world.
The smoke and the flames now.
Oh, the humanity!
Of the 97 people
onboard the Hindenburg,
13 passengers, 22 crew,
and one ground crew person
all perished in this event.
It's kind of
insane to think that
people started
jumping from the ship
in order to save themselves.
Some of them actually
died because of the fall.
Miraculously, about two
thirds of the people on
actually lived
through this disaster.
immediately suspect
that sabotage is involved.
Given that it is one of the most
visible spectacles on Earth and
has a giant swastika on it,
naturally, that would seem
to be the perfect target
to take down the Nazis.
So everyone immediately thought
there must have been a saboteur.
Because the Hindenburg was
used as a Nazi propaganda tool,
it's a natural target
for anti-Nazi activists.
The Hindenburg senior captain
Ernst Lehmann reports that
just before leaving Germany,
they received a warning
that there was a threat
to bomb the Hindenburg when
it was over American soil.
Hugo Eckener was the
head of the company
that built the aircraft, and
he would ultimately indicate
that he received threats,
directly, that the aircraft
should not proceed to
Lakehurst, New Jersey
because something bad
would happen there.
Given this warning,
the German security,
before taking off, was
extremely stringent.
They went through the mail,
they went through the luggage,
and nothing was found, but
this was early days of security
and something may
have slipped through.
Charles Rosendahl, a
commander of NAS Lakehurst,
suggested to the FBI
that they should
investigate a passenger
who had a dog in the
cargo compartment
right around cell six,
and he had been visiting the dog
unaccompanied by a member
of the ship's crew.
The man with
the dog is soon identified
as passenger Joseph Späh.
Joseph Späh is born in Germany
and then immigrates to the
United States as a young boy.
He's an entertainer in the
tradition of vaudeville.
He does monologues, standup,
he's also an acrobat
and a contortionist.
And he's been on
a tour in Germany
and now he's taken the
Hindenburg back home.
During the latter part
of his German tour,
he purchases an expensive
German Shepherd puppy named Ulla
to use in his act,
and he takes Ulla back
with him to America.
And so Ulla is in a kennel
and is kept in the cargo
hold of the Hindenburg.
Crew members
report that during the flight,
Späh insists on feeding
the dog himself.
The passengers aren't allowed
to simply wander to the
cargo bay on their own,
that's usually
what the crew does,
so this behavior gets
the crew's attention.
Several of the
stores report that
Späh was acting strangely.
In particular, when
the Hindenburg
was delayed for several hours
due to the thunderstorms,
he had this urgency to land.
He was getting impatient
when the Hindenburg
was not quite landing on time,
which if you had planted a
bomb that, say, had a timer,
would be a reasonable
thing to be doing.
As investigators learn more
about Späh's background,
suspicions deepen.
In addition to having visited
the inside of the
hull of the ship
without being accompanied,
Joseph Späh is a
professional acrobat.
He easily could have climbed
around the rigging of the ship.
So because of his
acrobat abilities,
he could have made
his way outside
of where he was supposed to be,
worked his way to the
tail of the aircraft,
climbed up a ladder
all the way to the top,
and placed a time bomb
somewhere on the airframe
between two hydrogen bags,
and that explosion could have
brought the aircraft down.
But even if Späh
had the means to plant a bomb,
what was his motive?
Although by this point, Späh
is officially an American,
he is German by birth,
and so maybe he thinks
that the rise of the
Third Reich in Germany
is bad for his homeland.
In fact, some of the
crew members on the ship
recall Späh making
anti-Nazi jokes on board.
He's investigated by
the FBI, but they find
that there's absolutely
no evidence suggesting
that he planted a
bomb on the aircraft.
The truth is, no one that
looked at the wreckage
ever found any
evidence of a bomb
or of any sabotage
of the Hindenburg.
Some people who look
at this feel that
the reason why Captain Pruss
and other bigwigs
from the company
were pushing this
idea of a saboteur
is because they wanted
to free themselves
from any responsibility
for this horrible tragedy.
As investigators search
for the explosions caused,
they turned to another clue.
There were storms
all over the area
of Lakehurst, New
Jersey that day.
And at the time of the
Hindenburg landing,
winds were gusting
at 30 miles per hour,
there was lightning,
it was chaos.
There's communication
from the ground command
and the captain on the ship.
The commander on the ground,
Commander Rosendahl,
he says the weather
is too strong,
the thunderstorms are too much
for the airship to come in.
And so the Hindenburg has to
circle around a number of times
because it's three
hours of storms.
Just because the
storm has moved out,
we're seeing cells
in the distance,
even upwards of
10 plus miles away
doesn't mean it's
not gonna impact.
But people may have
let their guard down,
thinking, okay, that
activity has passed.
But that activity,
it's still lingering.
At the time, the
New York Daily News
reports a number of theories
for what brought
down the Hindenburg.
The leading theory, lightning.
A typical lightning
bolt carries 300 million volts
and can reach temperatures of up
to 50,000 degrees Fahrenheit.
There's more than enough
energy when it comes
to lightning to
cause destruction.
We see that with forest fires
and even when it
strikes tall buildings.
And there's precedent
for lightning
striking a Zeppelin.
In 1917, a Zeppelin
was brought down
and 23 people were killed
when it was struck by
lightning over the Baltic Sea.
Another incident
occurred in 1923
when an airship called Dixmude
was struck by lightning.
It exploded in midair,
killing all 50 people on board.
But while the weather conditions
improved enough in
Lakehurst to begin landing,
some believe it's possible
that the Hindenburg is struck
by a rare phenomenon
called positive lightning,
which triggered the
terrifying explosion.
During the storm, there's
extreme electrical movement.
Negative charges build up
on the bottom of the clouds,
positive charges build up
on the top of the clouds.
This so-called
positive lightning
is a connection
between the ground
and the upper
reaches of the cloud
rather than the bottom
reaches of the cloud.
So it has to travel a
much greater distance,
and because of this,
the lightning strikes
from positive lightning
can be up to 10 times stronger
than negative lightning.
These positive lightning strikes
can happen 20, 30
miles from a storm,
so you can be without a
storm in your general area
and a bolt can come
out of the blue.
But those
who know the Hindenburg
question whether it can be
taken down by lightning.
The captain of the
Hindenburg, Max Pruss,
told investigators
that he'd flown
through lightning storms
in the Hindenburg
several times before and
the ship had been hit.
But he said the
lightning strikes
would basically just
cause some burn marks
on the outside of
the skin of the ship,
but there was no further damage,
so they were no problem as
far as he was concerned.
Witnesses on the ground
did not see lightning
as a factor.
There were many witnesses,
a thousand people on the ground
looking up at the Hindenburg,
and nobody saw a
bolt of lightning.
But that doesn't
mean the stormy weather
didn't play a role.
The Germans knew a fair amount
about how to safely
handle hydrogen,
and one of the
biggest rules of all
was you do not land a hydrogen
airship in a thunderstorm.
But they felt under
pressure to land,
and so they basically ignored
one of the oldest rules
in their own book.
There was a bolt
out of the blue,
a big flash that
happened in a distance.
It came at the top of the cloud
and you might not
necessarily see that.
So it's gonna strike
about 20 to 30 miles away,
it's gonna be very quick.
So potentially, they
may have just missed it
because it happened that fast.
In the wake
of the Hindenburg disaster,
both the American and
German governments
conduct investigations
into the cause of the
airship's explosion.
So, the investigation interviews
witnesses on the ground,
it goes through
all of the wreckage
that's in place
there at Lakehurst,
and it takes into account every
piece of possible evidence
that can be assembled
to put together a picture of
what happened to this aircraft.
In August 1937,
three months after the incident,
the US government
releases its report.
The official German report
is issued five months later.
Both come to
similar conclusions.
The Hindenburg is constantly
venting hydrogen gas
to help with steering,
to help slow it down,
and it is this hydrogen gas
that the investigators find
that is responsible for
the Hindenburg burning.
As to what
actually sparked that explosion,
neither report comes to
a definitive conclusion,
but many scientists
share the same theory.
When you have a
highly flammable mixture
of hydrogen and oxygen,
all you need is a spark.
On May 6th, 1937,
as the Hindenburg flies
from New York City
south to New Jersey, the
ship faces troubling weather.
Around 6:00pm, there's heavy
rain falling in Lakehurst
and lightning
strikes were reported
throughout much of the day.
Due to the storms, there's
so much electrical activity
that local rubber
factories are shutting down
because they have
powdered rubber
and powdered rubber
is combustible.
Like hydrogen, rubber
dust is incredibly flammable
and explosive.
So if it were to
come into contact
with a spark from
a lightning strike
or some other
atmospheric electricity,
that would be a bad situation.
By the time the
Hindenburg is ready to land
in Lakehurst, New Jersey,
it's already been pushing
through a high electric
field for hours
In the wrong conditions,
the Hindenburg's outer covering
can act as a conductor.
The German investigators
determined that
the particular formula used
for the dope for the fabric,
including the powdered aluminum,
creates a substance
that has the ability
to hold a charge
when it gets wet
and it was wet that day
because of the rain.
So what's happening
to the Hindenburg
is very similar to what happens
when you rub your feet on the
carpet while wearing socks.
It builds up an electric charge.
Then if you go and touch
an electrical conductor
like a doorknob
or a light switch,
that charge that you built
up wants to go somewhere
and that's why you get this zap.
It's an electrical
static charge.
For the
Hindenburg to go up in flames,
that spark needs to
come into contact
with something flammable.
Now, Hindenburg is
traveling with 16 bladders
full of hydrogen,
which is extremely flammable.
We know that the
aircraft probably
had a hydrogen leak in it
because as it's approaching
the mooring mast,
it's tail heavy,
nose high, tail down.
So they begin dumping ballast
from the after part
of the aircraft
to potentially
right the aircraft.
What the crew is doing is
treating a symptom,
not the illness,
and the illness was
there's a hydrogen leak
somewhere in the
tail of the aircraft.
At 7:21,
the Hindenburg arrives
at its mooring mast
and prepares to land.
The Hindenburg has
just gone through a storm
and it's accumulated
a lot of charge,
both on the skin
and the metal frame.
So as the Hindenburg
is coming into land,
it drops its landing lines
which are attached
to the metal frame.
So the metal frame is
grounded through those lines
and the excess charge
on the metal frame
can move into the ground,
meaning there's not as much
of a concentration of charge
on the metal frame.
So the skin, with a high
concentration of charge,
will want to go to that
lower concentration
and you get a spark.
So if a spark is generated
and it comes in contact
with free floating hydrogen,
there are gonna be
flames and an explosion.
Some critics
challenge this theory.
In particular, it's the timing.
The fire does not
ignite at the moment
the mooring ropes are dropped.
If the idea is the ropes
complete the circuit
and that's what
generates the spark,
then we would expect
to see the flames
at the moment the
ropes are dropped.
Instead, the explosion
happens four minutes later,
which could indicate
a different trigger.
In the months after
the Hindenburg goes down,
US and German investigators
agree on a key fact,
bad weather contributed to
the airship's explosion.
But could something
other than mother nature
have caused this
tragic accident?
On May 3rd, 1937,
as the Hindenburg departs
for Lakehurst, New Jersey,
the Zeppelin is already
a worldwide phenomenon.
The Hindenburg had had
an amazing year in 1936.
It had done seven round
trips to Rio de Janeiro
and 10 round trips to America.
So the Hindenburg's
maiden season
was really quite successful.
If you think about it, 200,000
miles, nearly 3,000 passengers,
with virtually no problem.
The record for the first
year was very strong.
The Hindenburg was looking
to do a very rapid turnaround
and head back to Europe
for the coronation
of King Georgia VI.
So because of that, there's
intense pressure on a captain
to get this thing on the ground.
Captain Max Pruss
prides himself on punctuality,
but by the time the Hindenburg
reaches Lakehurst, New Jersey
on the evening of May 6th,
the airship is already more
than half a day behind schedule.
There were strong
headwinds over the Atlantic
and now, weather and storms
in the northeast of America
is even pushing him
further behind schedule.
It was horrible weather and
so, anxious to land quickly,
Pruss decides to modify
his final approach.
He's no longer able
to go in a straight line
because the wind has shifted,
and so in order to put the
bow of the ship into the wind,
he needs to make a turn to
starboard, or turn to right.
The pilot is a
little bit further
out of position
than he wants to be,
and so the aircraft moves in
faster than it would
typically approach,
and then it carries out
this large swinging maneuver
to burn off air speed
to reduce that momentum
as it approaches
the mooring mast.
So it comes sort of hauling
in as fast as it possibly can,
which is not a breakneck speed,
but for that aircraft, it is.
Some people have
expressed a thought
that this final turn may
have overstressed the ship.
Some people on the ground
report having heard popping
inside the aircraft
during that last turn,
like something inside
of it went wrong.
As the Hindenburg
moves into its final position,
all hell breaks loose.
It's believed that the popping
that some people on the ground
heard during that last turn
may have been the
sound of the wiring
that secured the rigid
internal frame of the aircraft.
Maybe one of the wires snapped.
And that would've
explained the popping noise
that was heard by some
people on the ground
and that that last
turn had caused
that high tension
cabling to snap
and that it was somewhere
in the tail section
of the aircraft.
If a bracing wire snaps,
you now have this jagged wire
that's flailing about on
the interior of the ship
near some of the gas cells.
So a rusty, jagged wire
could then flail about,
hit one of the gas cells,
and cause a rip in it.
That rip then allows hydrogen
to leak out into the body of
the ship and mix with air.
With so much
transatlantic travel,
the Hindenburg may have
experienced wear and tear.
You have to wonder,
the Hindenburg was
constantly crossing the sea,
exposed to salty sea air,
which can add corrosion,
so that could have compromised
its internal structure somehow.
The bracing wires
were made out of steel.
The aluminum framework was
highly corrosive resistant,
but steel can corrode.
So over time, the Hindenburg
is accumulating humidity
and that moisture can
lead to corrosion,
which can also weaken
the bracing wires.
So if there was weakened metal
that was anywhere
within the ship,
once the captain started to
take those really sharp turns,
that could have
added more stress
on the framework
of the aircraft.
One of the broken wires could
have actually punctured a hole,
then the hydrogen cells,
that would've released
more of that hydrogen.
Hydrogen mixed with air
creates a very combustible
and flammable environment.
At this point, all
you need is a spark.
Boom, the Hindenburg
goes up in flames.
But the missing
piece from this is
what caused a spark
in the first place?
Observers on the ground say
they saw signs of a
different structural flaw.
There were some
witnesses on the ground
who said right
before the explosion,
they could see parts
of the outer covering
flapping in the wind
on top of the ship.
In 2020, some
80 years after the disaster,
author Michael McCarthy
discloses new evidence
he uncovered in German
archives that suggest
not only that this flaw
contributed to the crash,
but that the Zeppelin company
was well aware of the danger.
The Hindenburg, it turns out,
had a hidden structural flaw
that created a
destructive rattling.
The problem was the outer
cover, the aeronautical cloth,
which is supposed to
protect the vehicle,
actually was
rattling excessively.
And vibration bedevils
all kinds of machinery.
Vibration is the thing
that makes things break
down and fall apart,
and this is what was
happening on the Hindenburg.
They found that this flapping
was causing the metal ribbing
to rub up against the cells
that held the hydrogen gas,
basically chafing and thinning.
Germans learned about
this several months
before the tragedy and
they tried to fix it.
So what they decide to
do is tie off with cord
all the metal crossovers
so that they reduce
the amount of pressure
onto the gas bags,
and then they take
strips of tape
that are one and
a half inches wide
and they put 'em wherever
the gas bags had
been abraded before
as a protective measure,
and they resow the thing back
together, and off it goes.
So basically, the Hindenburg
is flying in its second season
with bandages on.
There's a belief that possibly
some of that patching work
ultimately broke loose during
the bad weather that
was encountering
over Ocean County,
New Jersey that day,
and that maybe some
of that flapping skin
was broken loose also by
whatever structure inside the
aircraft may have broken loose
during the high turns
that immediately proceeded
its final approach
to the mooring mast.
Proving this
theory is a challenge.
The hydrogen fire that
the Hindenburg encountered
was so severe, so strong,
that the physical evidence
is virtually non-existent.
There are pieces,
there are shards,
there are little things
in museums and so forth,
but the physical
evidence was virtually
completely destroyed.
For decades, most scholars agree
the Hindenburg was brought down
by an ignition of hydrogen.
Given how combustible
that gas is,
it seems like a
foregone conclusion.
Then in 1996,
a NASA scientist
named Addison Bain
proposes a
controversial new theory
that experts have targeted
the wrong part of the ship.
For years, the Hindenburg
was frequently used
as the example for the dangers
of using hydrogen as a fuel.
But while Bain was
researching hydrogen
for his own rocket booster,
he began to think that maybe
hydrogen was falsely accused.
Bain says his
first clue comes from the color
of the Hindenburg's flames.
Eyewitness testimony says that
they saw orange and red flames.
But hydrogen, when it burns,
it burns a light blue.
So maybe it wasn't the
hydrogen that it was burning.
Bain also says
that if there was
a hydrogen leak,
it would've left
a telltale sign.
Shortly before the
Hindenburg disaster,
there was a gas explosion
in the United States
that destroyed a school
and killed 300 people.
So the Germans were well
aware of the dangers
of using hydrogen
in these aircraft.
So to deal with that,
the Germans added an
advanced early warning,
which had an odor
component to it,
and it smelled like garlic.
We know there was crew
stationed near the
back of the aircraft,
but none of them reported
smelling garlic or the gas
before the disaster occurred.
Another thing that Bain notices
is that once the
tail of the aircraft
was engulfed in flames,
it still remained level.
So to him, that meant
that it was still buoyant
and hydrogen gas bags
were still intact.
So Bain comes up with a theory
that the plasticized lacquer
on the skin of the Hindenburg
is much more dangerous than
the hydrogen inside of it
because it contains elements
that, when combined,
are highly combustible
on their own.
The skin of the
Hindenburg is a cotton canvas
painted over with a substance
known as aircraft dope.
Aircraft dope is
a type of lacquer
that is used on a cloth
covered airship of some sort,
stiffens the fabric,
and it acts as a barrier against
water, wind, and objects.
The materials in
the lacquer contain iron oxide
and powdered aluminum,
elements used today
in rocket boosters.
Bain believes this ultimately
dooms the Hindenburg.
It was common practice
for lacquering
airships at the time.
So imagine that.
Take the stuff from a
solid rocket booster
and paint it all
over your airship.
Bain puts
his theory to the test.
He believes that the skin
would burn up just as quickly
as rocket fuel would,
so he gets actual fabric
from the Hindenburg
with that plasticized lacquer
which he thinks is combustible,
and he puts a very high
voltage, 30,000 volts
across that fabric, and poof.
It goes up in flames.
Bain believes that this
test proves his theory,
and that is that there
was an electrical arc
that didn't set off hydrogen,
but instead set off the aluminum
powder and the iron oxide
that make up the
skin of the aircraft.
When Bain reports his
findings, he says to the press,
"The moral of the story is,
don't paint your aircraft
with rocket fuel."
But Bain's theory
leaves some
questions unanswered.
It's very difficult
to conclude anything
from the color of the flames,
not only because the witness
testimony is unclear,
but more importantly,
but Hindenburg was not
a pure hydrogen flame.
It was a bunch of stuff.
You had a ship that
had fabric covering,
it had metal, it
had steel wires,
it had all sorts of
combustible materials
burning all at the same time
that contributed to whatever
color that flame was.
What's interesting about
the explosive paint theory
is that the photographs
we see of the explosion
don't show the canvas
going up in flames.
We see internal
flames in the ship.
Also looking at how it burned,
there's lines that run along
the locations of
those hydrogen cells,
which in the images,
it shows that the hydrogen
was actually burning
and not the canvas itself.
Anytime someone has
a sensational theory,
it naturally invites challenges.
And one researcher actually
looked at claims around paint,
and what he found was that
there was no possible way
that a spark could physically
ignite that dope material.
They've done experiments
using the chemical compounds
that were on the canvas
to estimate how long it would
take for the canvas to burn,
and the estimate
is about 40 hours,
not 34 seconds.
In 2000,
an 81-year-old witness to
the Hindenburg disaster
comes forward to tell his story
publicly for the first time.
He was just 17 when the
Zeppelin went up in flames.
Bobby Rutan was a child
of one of the Navy personnel
at the Lakehurst Navy Base
and he lived about 3,000 feet
from the site of the disaster.
He knew a lot about airships
because his father had
died a few years earlier
in a disaster with another
airship, the USS Akron.
As a teenager, Bobby
hung out in the hangers,
he sold souvenirs and
answered questions
from tourists who came
to view the zeppelins.
On the evening of May 6th, 1937,
Bobby is on the base and goes
out to watch the landing.
As the Hindenburg is coming in,
Bobby thinks he smells
some diesel fuel,
and then he hears what he
thinks is an engine backfire,
which makes him think
that the fire and the disaster
that he subsequently sees
is caused by the backfire
of one of the engines.
Hydrogen isn't the
only combustible fluid
that's on the Hindenburg.
It also burns around 300
pounds of diesel fuel
through the engines.
Diesel fuel is highly flammable,
so if it meets with
something that's hot,
say an engine block,
then the diesel fuel
itself can combust.
There had been recent trouble
with one of the
airship's engines.
A fuel pump on one
of the diesel engines
was replaced in flight,
but there's always
the possibility that
the installation of the new pump
might have been
completed incorrectly
and that there might
still have been
a problem with that engine.
So, some have suggested
that replacement caused
the engine to backfire
and result in the
ignition for an explosion.
As the
investigation gets underway,
Bobby immediately comes forward.
Bobby told Charles Rosendahl,
who was the commander of
the Lakehurst Air Base,
that he smelled this fuel
and that the backfire
could've ignited it,
leading to the explosion.
Commander Rosendahl
is having none of it.
He doesn't want to
muddle the story
because he believes
that it's sabotage,
and he doesn't want
Bobby saying to others
that there could be a
cause that has to do
with say, the engine.
He even tells Bobby's
stepfather that this
should not be information
that's spread around.
So why would Rosendahl do it?
He has two reasons.
One, he was the
one who suggested
that the airship
come in when it did
after circling for
at least three hours,
and of course, it
turned into a disaster.
So he has some personal
responsibility there.
But it's more than that.
He is a real protector
and an evangelist
for this form of flying.
Even when the technology
starts to fade
in terms of people's
enthusiasm for it
and the public's
enthusiasm for it,
he still continues to
be its main cheerleader.
So he doesn't want
this information out.
Bobby stays silent for decades.
He insists everything he
says he saw that day is true.
Years later, when asked
if the fuel that he smelled
could have come
from another source,
Bobby Rutan answers,
"Absolutely not."
There is nothing on the base
that it could have
given off that smell.
There's only blueberry
fields on one side
and sand on the other.
In 2007, the last
surviving ground crew member
corroborates Bobby's account.
Robert Buchanan
had been on the job
in 1936 when the
Hindenburg landed.
Buchanan recalls that as
the airship is landing,
the pilot does a hard maneuver
to slow the airship's descent.
Robert Buchanan corroborates
Bobby Rutan's account,
saying that he could see sparks
after the pilot completed
that hard right-hand turn.
He also heard the
backfiring engine
and even saw sparks
coming out of the engine.
Buchanan feels intense heat,
and he runs for the trees
It's so hot, he doesn't
think he's gonna make it,
but once he makes the tree line,
he looks back and he
sees flames erupting.
It's a dramatic account,
but not everyone is convinced.
These decades-old
memories add up.
The Commerce Department
interviewed hundreds of people,
not once did anyone suggest that
there was a fire or a spark
that began on the engines,
which were at the bottom.
And remember, fire
was at the very top.
It was a sawtooth flame
right along the tail,
nowhere near the engine,
so the distance
is simply too far.
The other problem with the idea
that the fire was started by
one of Hindenburg's engines
is that it is not credible
that anyone who was
located in the area
where the general public was
allowed to watch the landing
could possibly have
smelled anything
that was leaking or dripping
from an airship that was
almost half a mile away.
In addition to that, the
general public was in an area
that was right next to
the aircraft hanger,
which was filled with aircraft
that were all
powered by gasoline.
The Hindenburg's fatal flight
remains a topic of
enduring fascination.
There was no footage
of how it started.
The rubble was
completely demolished.
We don't have the evidence
to make a final conclusion
and so, we may never
know what happened.
Whatever triggered
the explosion,
it didn't just spell
doom for the Hindenburg,
but for the entire
rigid airship industry.
Two years after the disaster,
transatlantic airplane
passenger service begins.
A new age of international
travel is born
and the Zeppelin
fades into memory.
I'm Laurence Fishburne.
Thank you for watching
"History's Greatest Mysteries."
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