This week's 4.4 magnitude tremor in Los Angeles didn't do much damage, but it was along a fault that runs through a densely populated area.

And scientists warned that that fault has the potential of producing a devastating 7.5 magnitude quake.

It's again raised the question of earthquake preparedness in Southern California,

but it's not just the West Coast that ought to be thinking about that.

October 17, 1989, a 6.9 magnitude quake in the San Francisco Bay Area

collapses elevated highways in a section of the Bay Bridge.

Candlestick Park is evacuated as the World Series is postponed.

Broken gas means fuel fires that destroy buildings. 63 people die. Damages total more than

$6 billion. February 9th 1971. A state of emergency in California following the earthquake which disrupted the entire

state.

A 6.6 magnitude earthquake in California's San Fernando Valley leaves 65 people dead, some in the

partial collapse of a Veterans Administration Hospital. Damage is

estimated at $500 million. Quakes, many still vividly remember.

But a less well-known seismic event reshaped an area in the middle of the country

more than two centuries ago.

For two months at the end of 1811 and the start of 1812, a series of quakes and

smaller tremors shook the area around the tiny frontier town of New Madrid, Missouri.

The initial shock is estimated to have been about magnitude 7.5.

Witnesses said houses collapsed and the earth opened up.

Some said the Mississippi River ran backwards for a short time.

Trees snapped and geysers of water and sand shot up from deep underground.

The effects were in the epicentral area catastrophic.

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