Earthquake in US West Coast scenario

[Exploder]

I was just reading about some fiction on Wikipedia like Escape from LA and Demolition Man, in which a huge earthquake severely devastates the West Coast or even detaches it completely from the US mainland.So my question is, how possible is something like this to happen in the real world? Or is it just Hollywood?

[Red Menace]

Even though we have earthquake codes which all new buildings must meet "the big one" could still devastate California. The Northridge Earthquake of 1994 was only a 6.7 magnitude quake, it killed 72 people, injured 11,000 and cost the state $12.5 billion in damages. But, the Pacific Plate and the North American Plate slide against each other, so in a couple million years Los Angeles will be the largest city in Alaska but I doubt we will fall off completly.

[Jill]

History tells us there will be a big one eventually. As more and more humans occupy this earth....the more casulties will result in the long run.