All language subtitles for When.Big.Things.Go.Wrong.S01E04.Ripple.Effect.1080p.AMZN.WEB-DL.DDP5.1.H.264-BurCyg_track3_[eng]

ANNOUNCER: This program is
rated PG, and contains

ANNOUNCER: This program is
rated PG, and contains

ANNOUNCER: This program is
rated PG, and contains

mature subject matter.

Viewer discretion is advised.

(TRAIN DRIVER SPEAKING SPANISH)

NARRATOR: One of
the worst train crashes
in Europe's history.

There is people screaming,
there is kids screaming.

BOBBY: There's mothers
screaming out for their kids...

NARRATOR: But what caused
this catastrophe?

Something must've gone
really wrong for this train
to crash in this way.

(SIREN BLARING)

NARRATOR: Now.

Engineers unlock
the clues to the world's
biggest disasters...

(UPBEAT INSTRUMENTAL
MUSIC PLAYING)

(WOMAN SCREAMING)

NARRATOR: To find out
what happens when
big things go wrong?

(MAN SPEAKING INDISTINCTLY)

These are ultimate fears
that keep structural engineers
awake at nights.

MAN: Oh, my God!

NARRATOR: It's 8:31 p.m.
on a summer evening
in rural Spain.

The latest in high-tech
transport, the S730 train
is speeding north

towards Santiago de Compostela.

The S730 is built to bring
high-speed travel

to areas of Spain
that haven't had it before.

Particularly this area
that's furthest away

from the capital city Madrid.

NARRATOR: This train
is built for speed.

The S730 is one
of the newest designs
on the rails

and has been in service
for a year.

ROB: It offers luxury
with lightning pace.

NARRATOR: The train contains
11 pressure-sealed passenger
rail cars.

And can transport
nearly 300 people.

Onboard the packed train today
are 218 passengers,

including Texan, Bobby Fariza
and his wife Myrta.

I'm there all excited
because I love
high-speed trains.

NARRATOR: For them,
it's the vacation
of a lifetime.

On their itinerary,
a Spanish festival.

BOBBY: In Santiago
de Compostela,

they have what they call
the Fiestas Patrias.

It's a very big party.
You got over a million people

coming over for a span
of about ten days.

The fireworks are incredible.

And I was excited
because I wanted my wife,
Myrta, to see it.

NARRATOR: But
what the Farizas
don't know

is they're moments
from disaster.

As it closes in on
its final destination,

the train is travelling
at 120 miles per hour.

The train is hauling
and is going through

a series
of different tunnels.

NARRATOR: It's a section
the drivers navigated
countless times before.

As it exits the tunnel,
there's a sharp bend.

(DRIVER SPEAKING SPANISH)

NARRATOR: Drivers have
warned officials about
this notorious corner.

Trains must slow down to 50 mph
to drive through it safely.

The train tilts
to the side, like that,

when it's going through a curve,
whichever side it's going.

NARRATOR: But today the train
doesn't stop tilting.

All of a sudden it just
kept turning and turning.

Everything and everybody
that was on this side
of the train

was starting to fall
on our side.

And very violently
just went on its side.

(PASSENGERS SCREAMING)

That's when everything
went black and white.

(TRAIN HORN TOOTING)

The train goes around the curve,

we see the first car
makes it all the way around,

but then weird things
begin to happen.

If you're in the back,
you might have heard something

for like a second
right before you got thrown.

A loud bang,
or a series of loud bangs.

Lights go out, it's probably
like a bomb went off.

(CRASHES)

NARRATOR: The train is now
scattered

across hundreds
of feet of track...

A diesel generator car
is on fire.

Rescue won't be easy.

Bystanders and emergency
services begin a desperate race

against the clock,
to rescue survivors trapped
in the crushed wreckage.

It's carnage everywhere.
The trains have ripped open,

people have been thrown
out everywhere.

Seventy nine people are dead,

and almost everyone else
is injured.

NARRATOR: The crash
is devastating news.

The derailment or crash
of a high-speed train
in engineering terms

is a very surprising thing
to occur,

high-speed train travel
is renowned as being

one of the safest
modes of travel in Europe.

So when a high-speed train
in particular crashes,

everybody really sits up
and takes notice.

NARRATOR: What causes this state
of the art train to crash

with such heavy loss of life?

Answers to this mystery
begin back in 1990.

Spain is getting ready
to host the Olympic games
and a major world expo.

So it's a really big year

as Spain really arrives again
on the world stage.

NARRATOR: Thousands of visitors
need to move around the country
and fast.

Solution? Build a modern
high-speed electric rail
network

with 2000 miles of track,

enough to stretch
from New York to Utah.

The Spanish Government have made
the decision to invest heavily

in these new high-speed lines,

because new infrastructure
is going to bring
in more business,

more tourism
to the area's economy.

NARRATOR: The price tag...
a hefty $72 billion!

Technology and building
materials are key

to the high-speed
train revolution.

They also hold the first clue
to why this crash is so deadly.

The first new train model
to hit the tracks is the S130
in 2007.

Designing a high-speed train

isn't like throwing together
a slow brick shaped Amtrak,

it needs
to be aerodynamic,

and to go as quickly
as possible it also
needs to be light.

NARRATOR: Its aerodynamic nose

is designed to reduce
air resistance.

ROB: Some high-speed trains,
like the S130,

are built
like an airplane
on rails

using specialist materials
like aluminum

to keep the weight down.

NARRATOR: Aluminum
is three times lighter
than steel.

Helping trains reach
an incredible 155mph.

Twice the speed of older
models.

DAN: In many ways,
thinking of a high-speed train

is like thinking about
an airplane.

You have an aluminum tube
full of human beings.

That tube is lightweight
and designed for efficiency,

but not for crashworthiness.

NARRATOR:
But there's an issue.

Aluminum isn't as strong
as steel.

So, when a crash does occur
usually it's really, really bad
news for people on board.

I mean, think about taking
an aluminum can

and throwing it at a wall
made out of concrete,

the can is definitely
going to lose.

NARRATOR: And when
the Spanish train derails,

that metal is all that protects
its passengers.

Making the wrong choice
in material can be disastrous.

A lesson learned on US
Speedways in the late 1960s.

IndyCar racing. The ultimate
combination of man and machine.

And its fans are growing.

NARRATOR: Designers need
new components
to build winning cars.

New materials meant IndyCar's
could go faster than ever.

And accelerate
at shocking speeds.

NARRATOR: And the material
they turn to... aluminum.

The cars became lighter
and would move faster
down the track.

So new speed records
were being made.

MAN: With an average
of 147 miles an hour,
a new record time...

NARRATOR:
But as speeds increase,
so does the danger.

MAN: The track is filled
with flying wheels
and other auto parts.

Setting off the worst
chain reaction accident
in Indianapolis history.

SIAN: The thing about aluminum
is it's super lightweight,

but it's not really resistant
to breakage,

and so it's great
when you wanna go fast,

but it's terrible
if anything goes wrong.

MAN: The red flags are out
and the track is alive

with firemen, ambulances,
officials and pit crews.

When cars would crash,
these new materials
weren't as strong,

and there were some
very, very serious accidents
back in those days.

NARRATOR:
During the '60s and '70s,

fifteen drivers die
in these lightweight cars.

MAN: Dave MacDonald loses
control of his juggernaut
and spins into the wall.

It starts a chain reaction
as others pile up.

Seven cars are involved.

Eddie Sachs smashes
into MacDonald and askew.

MacDonald dies later
in the hospital.

NARRATOR: Then,
in the 1980s, engineers find

a safer alternative,
carbon fiber.

Deaths fall by 87 percent.

In the Spanish train crash,
aluminum coaches crumple
like tin cans.

Which helps explain
the high death toll,

one third of the passengers
lose their lives.

But why does
the train fly off the tracks
in the first place?

Coming up...

More pieces
to the puzzle uncovered.

ROB: You have to have
the weight in the right place
at the right time.

And if it isn't, you are in
for a whole lot of trouble.

NARRATOR: And later,
a 747 tragedy shows
what happens

when big things...
lose their center of gravity.

(DISTANT EXPLOSION)

NARRATOR:
When big things go wrong,

engineers have
to find out why.

In the Spanish train wreck,

building cars from lightweight
metal proves fatal.

Aluminum is not designed
for crashworthiness.

It's actually designed
for fuel efficiency
and high-speed.

So, if their crash does happen
with those particular vehicles,

it's really, really bad news
for the people on board.

NARRATOR: But aluminum
didn't cause the accident,
so what else did?

By 2012, Spain's high-speed
rail revolution is proving

so effective that more regions
want to be a part of it.

The availability
of a high-speed
rail network

covering all of Spain
increases accessibility

for passengers and generates
competition for both
road and air traffic.

NARRATOR: But these remote
areas have old track
that's not electrified.

And new high-speed trains
can't run on it.

There's the current situation
where you've got both

new electrified track
and older non electrified track.

And to electrify
the whole country

will take a lot of money
and a lot of time.

NARRATOR: It's an
expensive problem.

But there's an easy solution.

Change the trains, so they
can run on both types of track.

What they did was add two diesel
engines to an S-130

in order for it
to generate its own
electricity,

and to be able go to the places
they couldn't go before.

NARRATOR:
A new hybrid train is born.

Renamed the S730, it generates
its own power when it needs to.

ASEGAN: It's similar
to, like, a plug-in

extended range hybrid
like a car,

in the sense that
it can plug into the track,
so to speak,

get its electricity
from the track
and that can drive it,

which essentially is being
driven by a power plant,
which is elsewhere.

Or you can drive
with its own onboard engine.

NARRATOR: This lets
the S730 high-speed train
travel anywhere in Spain.

This versatility
makes it the toast

of the Spanish railway industry.

NARRATOR: But there's an issue.

This new train
develops a reputation
amongst its drivers.

They refer to it
as the Frankenstein

or a train
that's been cobbled together

from different pieces,

if you think of the old monster
with scars and bolts

coming out of its neck...

It's not a compliment.

NARRATOR: Adding
two diesel generators
means extra weight.

Over 158,000 pounds per train.

ROB: The extra weight that's
been built into these trains
isn't a problem per se.

But the fact that

these great hunky
diesel generators

sit higher up in the cars

means that the center of gravity

of those carriages
has now been raised.

This new train's specifications
says that it shouldn't be

more than 40 tons heavier
than the original train.

But it's actually
72 tons heavier,

and this makes
a big difference when
you're going fast.

NARRATOR: It's a dangerous
design choice.

The problem with having
a higher center of gravity
for a rail car

is that it becomes less stable
around the corner.

It's easier to tip over.

And that is the consequence of
adding a diesel generator car

to the S130 high-speed train.

You have to have the weight
in the right place
at the right time.

And if it isn't, you are in
for a whole lot of trouble.

NARRATOR: A shift
to the center of gravity
can cause serious trouble.

As one crew discovers
at a US airbase in Afghanistan.

April, 2013.

Bagram air base.

A cargo plane carrying
military vehicles takes off.

Every plane that takes off
is finely tuned to have
perfect weight and balance.

This is why your luggage
is weighed

every time you go
to the airport.

NARRATOR: All seven crew
die in the crash.

This 747 is fully loaded.

It's carrying five
armored vehicles.

Each weighing 40,000 pounds.

This kind of cargo
must be evenly distributed
and secured.

What now happens is
if a strap breaks

that was used to hold
these things in place,

the weight just shifted
around inside the plane.

When that weight shifted
to the back,

it's going to change
the balance inside

and cause it
to tip backwards.

SIAN: Once this shift
in weight happens,

there was nothing
the crew could do.

It's a series of events

that all go wrong.

It starts with something
really small,

you know, a strap or harness

which ultimately
just comes down to some guy
hooking it up.

And it doesn't work...
and the whole thing goes down.

(DISTANT EXPLOSION)

-NARRATOR: Coming up.
- (SIREN WAILING)

More clues are revealed.

When trains are moving
at really, really high-speed,

the relationship
between that speed
and the human reaction time

becomes a very, very
important component
in operating a train safely.

NARRATOR: And a cruise ship
is on a collision course.

-MAN: Hold on, hold on!
-WOMAN: Hold on!

NARRATOR: Trains are some
of the fastest and largest
machines on Earth.

So when they go wrong,
the results can be
catastrophic.

They crash for all kinds
of reasons.

Mechanical failure.

Foreign objects.

MAN: Oh, my goodness!

NARRATOR: And driver error.

As in this deadly crash
in Los Angeles.

Even still, it's one
of the most reliable modes
of transportation.

(CRASHES)

So the Spanish high-speed train
derailment is baffling.

DAN: Statistically it's much
safer to travel

via rail, or train,
than it is in a car.

This is the question,
why did this happen
to this particular train?

NARRATOR: The train
has a lightweight body

and it's Frankenstein design
makes it unstable.

But these only become a problem
when it travels too fast.

(HORN TOOTING)

NARRATOR:
Was that the case here?

1992, Spain's new trains
are designed to travel

at 155mph on straight tracks.

But in parts of the country,
straight routes are impossible.

The area of Galicia
that this train line
has been built in

is incredibly mountainous
and rugged.

And so engineering
a straight flat rail line

for tens of kilometers
to allow a high-speed track

is an extraordinary
civil engineering challenge.

And in the end,
they end up having
to build 31 tunnels

and 38 sections of viaduct
in order to get the track
across this countryside.

NARRATOR: When trains
approach Santiago,
they must slow down

to 50mph to navigate
the very sharp corner.

If the driver gets it wrong,
they're in trouble.

When trains are moving
at really, really high-speed,

the relationship between
that speed and the human
reaction time

becomes a very, very
important component
in operating a train safely.

There's just less time
to react to dangerous
situations,

but the driver has to do it
in order for the train
to be safe.

It's a very, very high pressure

and very demanding
job environment.

NARRATOR: Records show that
on the night of the crash,

the train approaches
the corner at 121 mph.

(TRAIN HORN TOOTING)

With the last warning sign

is just 500 feet
before the bend.

There's simply not
enough time to react.

Even if you do react quickly,
it's gonna take a long time
for your reaction

to manifest in what
the train then does.

Even though we consider these
to be lightweight trains,

these trains still weigh
many, many, many tons.

So to stop such a massive
vehicle in a short amount
of time is very difficult.

You need a significant amount
of time and warning to go

from a hundred miles an hour
to zero miles an hour.

It doesn't happen
in a blink of an eye.

NARRATOR:
Something all too familiar
to one cruise liner captain.

Venice, Italy. A regular
stop-off for cruise ships.

Including some of the biggest
on the seas.

ROB: The MSC opera
is an enormous cruise ship,

it's 902 feet long,
and weighs over 65000 tons.

That's the equivalent
of ten Eiffel towers.

NARRATOR:
Venice's ancient sea-lanes
are a tight squeeze.

The ship's been built
with a plethora
of safety features.

She has state
of the art navigation
and forecasting equipment.

And the crew and the captain
have been here hundred
of times before.

This should be
a routine situation.

NARRATOR: The captain must get
the approach speed just right.

But this cruise ship
doesn't slow down.

(INTENSE MUSIC PLAYING)

(SHIP HORN TOOTING)

(MAN SPEAKING)

(LOUD CRASH)

As the MSC Opera
is approaching Venice,

there's a problem
with the engine.

And rather than
the engine turning off,

the throttle
is turned on full thrust.

This is a known problem on ships
that's not all that uncommon,

but it usually happens
way out at sea

where there is a chance
to react.

Nearer to the land...
this becomes a massive issue.

NARRATOR: The crew
makes a final attempt
to slow the ship.

Two tugboats try to guide
the ship away from danger,

but one of the steel
cables snaps.

The pilot deploys both
of the MSC Opera's anchors
to try and slow the ship.

But it has very little effect.

It's still moving at speed.

NARRATOR: It's now unstoppable.

(MAN AND WOMAN SPEAKING)

This is a boat
that's 14 decks high

coming at you at full tilt
as you're stood on the dock.

And clearly your only instinct
is gonna be to get out
of the way

as quickly as you can.

Even when it hits solid ground,
the ship keeps moving.

65,000 tons of inertia
refusing to stop,

until it finally
grinds to a halt.

NARRATOR: People run
for their lives

as The MSC Opera
slams into the city.

(MAN SPEAKING)

(WOMAN SPEAKING)

NARRATOR: Five are injured.

The damage runs to hundreds
of thousands of dollars.

But everyone involved
escapes with their lives.

Passengers on the Spanish
high-speed train...

aren't so lucky.

Coming up...

Was this tragedy
just due down to driver error,

or could a new clue reveal

why the train
is travelling so fast?

To switch that system off
and still run it at high-speed

is absolute insanity.

And a Gulf of Mexico
oil-platform shows
how failsafe systems...

don't always work.

This ended up being
the worst oil spill

in the history of humanity.

NARRATOR: Big disasters
can have an obvious cause.

But sometimes finding answers
is more complicated.

Especially in a high-speed
rail crash.

In the aftermath of the crash,

you have
considerable destruction,

you have rail cars
leaning over on their sides,

some of them turned upside down.

One car, which is essentially
stood on end,

leaning up against
a concrete retaining wall.

High-speed trains like this
are not supposed to crash.

They are designed
to have some of the safest
technology available.

NARRATOR: So what happened
to the safety systems
on the Spanish trains?

Spain's new high-tech trains
are designed with computerized
safety systems.

Basically an electronic system
that constantly monitors

where a train is
at any one time.

How fast it's going,
and what's coming up ahead.

NARRATOR: And crucially,
there's an automated brake.

If the train's going too
fast, this system should
slow it down.

This is very much akin
to what they're starting
to put in cars now,

which are also
emergency auto-braking systems,

where if you're driving,

you're too close to the car
in front of you,

that car stops, um,
not only does it alert you,

but it also can stop
the car itself.

A system like this
could save lives.

NARRATOR: So accidents
caused by human error
should be impossible.

But after just a week
in operation, the S730
has a hiccup.

There are malfunctions
with the automatic
braking system,

and the error causes trains
to come to a halt.

NARRATOR: When trains switch
from new track to old,

the automatic brake kicks in
even at safe speeds,

causing delays that cost money.

So now a decision is made
to turn off the automatic
safety braking system

on this particular model
of train in this particular
section of line.

NARRATOR: Now, monitoring speed
is all on the driver.

You absolutely need
a failsafe system that acts
as a safety net

to catch any mistakes
the driver might make.

To switch that system off
and still run it at high-speed
is absolute insanity.

NARRATOR: It's a recipe
for trouble.

A working failsafe is crucial
in any complex machinery.

As the crew on a mega
drilling rig in the Gulf
of Mexico experienced.

Drilling into a pocket
containing over a million
gallons of crude oil.

This is one of the most complex
machines on the planet.

It's extremely dangerous
because what makes things
explode is pressure, right?

And at the same time,
the thing that's at high
pressure is combustible.

NARRATOR:
But on April 20th 2010,
the unthinkable happens.

(FIRE CRACKLING)

Just hours before, the crew
perform routine maintenance.

Capping a freshly drilled well
with concrete.

This is standard procedure

to cap it off,
so it doesn't leak oil

or anything else into the sea.

They do a pressure test

to determine if the concrete
is holding and they completely
misinterpret the results.

They think everything's fine,

but they couldn't be further
from the truth.

NARRATOR: A surge
of natural gas and oil

blasts through
the concrete seal.

Engineers activate
the rig's failsafe system,

the blow-out preventer.

A mechanism designed
to close the pipe.

You had these safety systems,

they're supposed
to be able to kick in
and cut the pipe,

shut it down, turn it off
and none of them worked.

NARRATOR: Natural gas
shoots up the drill,
and ignites.

(FIRE CRACKLING)

Eleven die in the blast.

The 300 foot flames can be seen
from 35 miles away.

And 4.9 million barrels
worth of crude oil

leaks into
the Gulf of Mexico.

I mean, this ended up
being the worst oil spill
in the history of humanity.

NEWSREADER:
The well maybe capped,

but the oil
is still gushing
out of control.

A torrent of crude soaking
Louisiana's coastline...

creeping all the way to
Florida.

Now the lesson
from Deepwater Horizon
for us is that

we can't rely purely
on technological solutions
to ensure failsafe.

And neither can we rely
purely on humans

to make the decisions
that are gonna give us
our failsafe.

We have to use them
in harmony with one another.

NARRATOR: Coming up...

With the fail safes disabled,
this high-speed train
is left vulnerable.

The driver suddenly realizes
where he is

and hits the emergency breaks,

but it's too late.

NARRATOR:
When big things go wrong
the results can be devastating.

-(PEOPLE SCREAMING)
-Bridges collapse.

Ships sink... and planes
fall out of the sky.

(PEOPLE SCREAMING INDISTINCTLY)

NARRATOR: But for people
involved in these tragedies,

the day often begins
like any other.

The 04155,
a hybrid high-speed train
is about to leave

the Spanish capital, Madrid.

218 passengers
are boarding...

including Texan, Bobby Fariza
and his wife Myrta.

Here comes the train
and, so we get in.

The train was so packed.

We sit down,
all excited with the train ride,

and, and the train
just runs smoothly.

As we go along,
we eat a little,
go to the cafeteria.

Keep watching our suitcases
because they're all the way
up there in the front.

And, uh, just enjoying it.

NARRATOR: The train reaches
its top speed

as it cuts through
the Spanish countryside.

It heads through
a series of 31 tunnels.

Imagine going down this line

where you alternate tunnel
to bridge, to tunnel to bridge,

and the only thing that
you have as a driver

to keep track of where you are
is visual cues.

They had announced
that we are arriving
to the train station.

Um, my wife, she then,
um, says to me,

"Oh, Bobby, I bet you,
you want to go straight
to the door knowing you."

And so it was one of those,
"Okay, honey. Yes, honey."

So, I sat down,
I did not go to the door.

NARRATOR: At this point,

the driver needs
to start slowing the train down

from its current speed

of 120mph to navigate
the dangerous corner.

If the driver hasn't started
braking four kilometers
before he gets to the curve,

he isn't gonna
get around safely.

NARRATOR: But at the worst
possible moment...

The phone rings.

(INDISTINCT CHATTER)

Now, the idea that
they could take phone calls
and all these things,

in the midst of that is, like,
really a recipe for disaster.

Particularly when you
got a section

of the route
where, like, it hinges

on the driver actually slowing
the train down.

It seems utterly utterly,
utterly incomprehensible

that someone would be
phoning the train driver

as they are approaching
this curve which is known
to be dangerous.

NARRATOR: The train
heads down a short slope,
picking up speed.

BOBBY: My wife,
she then says to me

if there's anything
that she needs to carry?

So I pick up, I went ahead
and I'm picking up my backpack.

NARRATOR: The train
approaches the final tunnel
before reaching Santiago.

After spending
over a minute on the phone
the driver hangs up.

(TRAIN DRIVER SPEAKING SPANISH)

You got to imagine,
you're travelling
at a high rate of speed

and you're looking
for landmarks.

So the moment you take
your eyes away,

even to pick up a phone,

by the time you look back up,

your scenery has changed.

And for you to be able
to recognize that,
is not easy.

NARRATOR: The train exits
the last tunnel

and speeds past
the final warning sign

of the approaching corner.

The driver suddenly realizes
exactly where he is
on the track.

Just a few hundred
meters away from the corner.

He throws down his phone

and slams
on the emergency brakes.

NARRATOR: But it's too late.

(LOUD CRASH)

That's when everything went
black and white.

And I, in my corner of my eye,
my wife was still there.

And then all of a sudden
I could see her go like this.

Um, she hits with her head
on the little table

that's in the back of the seat.

I had, you know,
a feeling that this
was not gonna be good.

And that's it.
I was knocked out.

(HORN TOOTING)

NARRATOR: In just a few seconds,
the train derails,

trapping passengers inside.

Still in shock,
the driver calls for help.

(TRAIN DRIVER SPEAKING SPANISH)

(SIREN WAILING)

I wake up, and I look around,
I'm thrown on the floor.

I feel a lot of pain
in my back,

and a lot of pain
on my hips, my knees,

and especially on my hip,
on my right side.

But with all the energy
and of course all
the adrenaline,

I realized that
I could stand up.

That's when I get to see
the whole scene.

It is just like a scene
from Hollywood.

You've got train crashes
all bent up.

There is people thrown
on the floor, all bangled up.

There's people screaming,
there's kids screaming,

there's mothers screaming
out for their kids.

I'm yelling out for my wife.

All I could hear
was this one guy,

he's screaming out
for his mom,

and he has an
ear hanging out.

We are the only two in there

that actually got up
out of the 40 something people

that were in that
in that car.

A lot of people
from the neighborhood
came inside

and started pulling out people,
and started to help.

They started pulling
out my wife...

She was conscious.
I could see that she
was not doing too well.

We pray together,
the Lord's prayer.

She couldn't say it,
but she was holding on.

And every time
would squeeze my hand...

(STUTTERS) as I said
the Lord's prayer.

NARRATOR:
Bobby's wife Myrta dies.

The crash takes a grim toll.

Everyone onboard
is injured or dead.

It's like, all the wrong things
coming together

at the right moment.

(SIREN WAILING)

(MAN SPEAKING SPANISH)

NARRATOR: In Spain,
Engineering compromises

and bad decisions have led

to one of the worst railway
disasters in its history.

A high-speed train packed
with 218 passengers
has derailed,

slamming into a concrete wall.

Seventy-nine die.

It shocks the world.

But seen through the eyes
of modern engineers,
it's not a surprise.

This tragedy would have happened
one way or the other.

There were just too many
deficiencies in the system

to allow it to operate safely.

NARRATOR: Aluminum
that crumples
in the crash.

Lightweight materials
just aren't as tough
when things go wrong.

NARRATOR: The train travelling
too fast.

Being a high-speed train driver,
getting a phone call
right at a critical moment

when you need
to be paying attention.

NARRATOR: Extra weight
from the diesel generator cars

throws off the train's
balance.

It becomes less stable
around a corner. It's easier
to tip over.

NARRATOR: A safety system
fall back is switched off.

It's really inconceivable to me
that anyone would turn off

the automatic braking system
intentionally.

and leave the only protection
of the train and its occupants
to the single driver.

That is just shocking.

It's like this combination
of human error and design error.

NARRATOR: But what happens
in the final moments

as the train
approaches the corner?

(LOUD CRASH)

It starts with the tiniest clue
that something
is not quite right.

The floor starts wobbling...

as forces it's not designed
to take start coursing
through its metal shell.

The first car to derail
is the top heavy
diesel generators.

They drag the rest
of the train off

causing this accordion
like destructive event.

And then all hell breaks loose.

The driver car
at the very front, he doesn't
have most of the mass,

the mass is right behind him,

and so as he goes
around the curve,

the big mass behind him
yanks everything else

and slings it up against
the side wall.

SIAN: The cars they crash
into each other,

piling up and splitting open.

We can see the violence
and all the kinetic energy

that is trapped in this train
being released as the debris
goes everywhere.

Order turns to chaos,

the forces take over,

the cars are now projectiles
flying through the air.

NARRATOR:
For Texan Bobby Fariza,

will never forget
that moment.

This is in the car
that we were in.
Car number 7.

And, uh... My wife and I
were sitting on this side, here.

And, uh, everything that's
on this side of the picture
went over to our side

when the car
flipped over on its side.

NARRATOR: In the end,

the train driver is held
to blame for the crash.

For victims,
there is no consolation.

BOBBY: We were college
sweethearts.

I miss her incredibly.

The loneliness without my wife
is incredible.

That is something
that I had to learn
how to deal with,

and start a whole new life

without having her.

It's not that easy.

NARRATOR:
In the immediate aftermath,

Spain reinstates
the automatic braking system.

And around the world,
high-speed rail services
make changes,

including in the US.

The Acela Express
that's been running
for two decades

between Washington DC
and Boston,

has the fastest trains
in America

with speeds up to 220mph.

NARRATOR:
After several high profile
derailments,

Amtrak and other
local rail systems

are making safety
an even greater priority.

Among their efforts,
installing smart energy
braking systems

to detect changes
in track layout

and monitor rail traffic.

Ride on this train
and there's backup technology

to prevent
an accident happening
in the first place.

And in my opinion

that's exactly how it should be.

NARRATOR: Every time
a big thing goes wrong,

engineers learn from mistakes.

To build smarter,
faster and stronger.

(INDISTINCT CHATTER)

MAN: Oh, my God!

(CRASHING)