The horrifying tsunami (search) that devastated the coastlines of Southeast Asia and Eastern Africa on Sunday has raised an unnerving question for Americans:

Could it happen here?

Alaska (search) has been hit by massive earthquakes in the past, and is still at risk. So is Washington state. Both are bordered by 700- to 800-mile fault zones.

So the U.S. has installed an early-warning system that reads the speed and direction of tsunamis — which are generally undetectable until they hit the shore because wave energy travels very deep and at near-supersonic speed underwater.

"We live in an area similar, and we should not lull ourselves into thinking it could not happen to us," said Eddie Bernard of Pacific Marine Laboratory (search) in Anchorage. "It could happen to us."

Click in the box near the top of the story to watch a report by FOX News' William LaJeunesse.