National Geographic's Nature's Fury

That has got to be a violent tornado.

Get those kids in that basement. Get 'em in that closet.

Get away from the windows. Get away from the windows.

Get away! Get away!

People underneath the girders of this overpass.

They're still hanging on.

Oh my God, we're having an earthquake.

Wait a minute. Hold on. Hold on.

Can you feel that? There go the lights. Oh!

We have a major fire burning near San Francisco's marina district.

We have the band now approaching the coast.

So we're just starting the long period of about 12 to 16 hours

when we're going to experience the thrust of this hurricane.

Can we spend most of our lives learning how to control ourselves

and our environment?

And suddenly, you wake up with the realization

I am not in control.

In cities all across the world, we go about our daily routines,

secure in our surroundings,

confident that our lives are orderly and predictable.

But at any moment, that confidence can be shattered,

as nature demonstrates that it still has the upper hand.

When we least expect it,

when we're least prepared, disaster can strike.

And few disasters are as unsettling as an earthquake.

The quake that hit San Francisco on October 17, 1989

was actually centered 50 miles away,

near a mountain called Loma Prieta.

Even in an area accustomed to earthquakes,

this one struck like a hammer.

It was tremendous, believe me. I just held on to dear life.

There was a sudden movement like this,

shaking, whole store rattling.

I mean, the roof, everything, the beams.

My TV screen popped out, and glass began to break,

you know, things like that.

Big marble table flew across the room

and shattered like glass almost.

The Loma Prieta earthquake lasted only 15 seconds,

but in that quarter minute,

northern California suffered six billion dollars in damage,

and 62 people lost their lives.

Earthquakes are not nice.

The ground is moving beneath one

the very essence of stability is questioned.

And that's quite apart from the damage,

the destruction, the deaths.

There's something awful about an earthquake

and it's not fun at all.

My guess is that earthquakes are really so scary

because you don't have any warning.

It's the only thing besides a nuclear war that can really

one second you're living in a big beautiful city

and ten seconds later, it's flat.

Earthquakes leave their trail of destruction on every continent.

In 1948, the city of Fukui, Japan

was leveled by a tremor several times

more powerful than atom bombs that destroyed Hiroshima and Nagasaki.

Mexico city was struck by a huge earthquake in 1985.

Nearly 10,000 died in the greatest disaster in Mexican history.

In September 1993,

a quake devastated the Indian state of Maharashtra.

In spite of warning shocks, most of the victims were asleep

when their houses collapsed around them.

Every day the earth is shaken by hundreds of small earthquakes.

Most go unnoticed.

They usually occur along the boundaries of the thin plates

that cover the earth like an eggshell.

Driven by the heat deep within the earth's core,

the plates grind against each other along lines call faults.

When the plates find their motion blocked, stress builds up.

Finally the fault gives way.

The released energy races through the earth

in the form of seismic waves.

One place where the boundary between plates

is dramatically evident

is the 700-mile-long San Andreas fault.

This is the source for most of California's earthquakes.

But for California, as for much of the world,

the movement of plates like these

is also an indispensable creative force.

If we didn't have earthquakes,

if we didn't have this great flow of heat

from the interior of the earth,

the earth would be a cold, dead place.

If it wasn't for this great flow of heat,

there'd be no continents, no oceans, no atmospheres,

the earth would be as dead and dry and cold as the moon.

Everywhere you look in California,

the hills are really created

by, by the action of the earthquakes, for the most part.

It's really the earthquakes

that create the topography, the valleys, the mountains,

control the river streams, where things go.

Earthquakes have been shaping the landscape of California for eons.

It's only in the last few hundred years

that civilization has gotten in the way.

Around the turn of the century,

San Francisco was a booming metropolis,

an emblem of California's newfound prosperity.

But on April 18, 1906,

that prosperity was shattered by the most famous quake

in American history.

Most of the city was destroyed in the tremor

and the fires that followed.

Much of charred rubble from those fires

was pushed into San Francisco Bay, adding to an existing landfill

that eventually became part of the city itself.

Today, that landfill lies beneath a section of the marina district.

This was the area hardest hit in the 1989 quake.

The problem here is the rubble from the tremor of 1906,

buried underground.

Shaken by the new quake, it literally fell apart,

and so did much of the neighborhood.

The practice of building on such unstable ground

is a problem throughout the world.

Mexico city was built on top of a dried-up lake bed.

The 1985 quake was actually centered hundreds of miles away,

but it turned the soft land under the capital

into a nearly liquid mass.

The buildings simply collapsed;

victims were crushed under tons of concrete and steel.

It's a modern nightmare:

Urban infrastructure crashing down around us.

As geologists and engineers like to remind us,

earthquakes don't kill people, buildings do.

Certain structures, like bridges and freeways,

are especially vulnerable to tremors.

In San Francisco's quake,

most of the deaths occurred on the Nimitz Freeway,

when a one-and-a-half mile section of the upper deck collapsed

on the roadway beneath.

Ed McVey was driving a freight truck when it happened.

There was no traffic.

I was doing about 55,

and all of a sudden it felt like I had a blowout.

I had no control over the truck.

Luckily, there was nobody beside me

because I was just all over the place.

I hit the brakes.

In the rearview mirror,

I could see what looked like the freeway falling,

and that didn't make any sense.

I saw cars and trucks disappearing underneath the rubble.

And I just knew I was dead.

I had no way of getting out of it. There was nothing I could do.

McVey was lucky that day:

His truck just happened to stop

under the only section of freeway that didn't fall.

I don't deal with it as well as people think I do.

I can be driving along anywhere,

and all of a sudden I've got freeway falling down on top of me.

Ed McVey escaped without a scratch.

Forty-two other motorists died.

Five years later, when an earthquake hit Los Angeles,

there was a similar freeway collapse.

Fortunately, the tremor struck before dawn,

when the road was virtually empty.

Next time this could happen at rush hour.

Yet overall, in spite of the freeway disasters

and the loss of some apartment buildings and houses,

San Francisco and Los Angeles weathered their tremors

extremely well...

largely because most of their tall buildings were constructed

with earthquakes in mind.

Too often, in other parts of the world, that's not true.

In December of 1988,

a relatively mild tremor struck the Armenian city of Leninakan,

and its acres of cheap, shoddily constructed housing.

Eighty percent of the city was destroyed,

and more than 25,000 people killed.

Specially trained dogs were brought in

to help locate survivors and victims

standard practice in such urban catastrophes.

Fortunately, Leninakan was a small city.

Tang-shan, in northern China, was not.

Just before dawn, on July 28, 1976,

an earthquake tore through Tang-shan.

It was the first quake in modern history

to score a direct hit on a major city.

As nearly as anyone can tell,

it left close to a quarter of a million people dead.

Entire families were wiped out,

so it was impossible to find out from the survivors

exactly how many had perished.

Besides falling buildings,

earthquakes create other special problems in urban environments:

Broken gas lines spark fires,

and broken water mains can make fire fighting nearly impossible.

We have a major fire brewing

in San Francisco's Marina District.

In the 1989 quake,

the San Francisco Fire Department

battled 34 major blazes simultaneously.

With underground water supplies cut off,

fireboats had to be used to pump water from San Francisco Bay.

Unfortunately, earthquakes in large cities,

with their accompanying horrors, are not rare events:

When you look at a map of the world

and plot the truly great cities of the world,