The quake hit at 5: 46 a.m. while many lay sleeping, woken by a moving earth underneath them. For twenty seconds the people of Kobe, Japan waited for the horror to stop. The quake left over 4,800 dead (at last count), a major city in danger, and millions wondering if this would happen to them.

The increasing science of prediction is still not very exact. Seismologists are good at knowing where conditions are right for an earthquake, yet it is almost impossible for them to say when the actual quake will take place. Some predictions have been right on the money, while others are not.

For example, no one predicted the Northbridge quake that caused more than 20 billion in damages in the San Fernando Valley last year. On the other hand, U.S. Geological Service gave many warnings about a quake to come from the San Andreas fault in 1988. Sure enough, on Oct. 17, 1988, while millions watched the Athletics take on the Giants in baseball's World Series, a quake hit and devastated the Oakland/San Francisco area. Leaving people to wonder when the Big One would actually hit.

"The Big One" is supposed to hit Southern California within the next 30 years. So the big question now is where and when will it occur. It could be anywhere from Santa Barbara in 2017 to Santa Anna in 1996. But experts in the field of seismology believe the "Big One" will definitely hit.

So predicting earthquakes isn't exactly precise yet, but seismologists are warning local governments to prepare. Some cities that are being warned include New York, which, even though a large quake is unlikely, is unprepared for even the slightest shaking, which could cause much damage to the high-rise buildings. Seattle, also, could have a quake, where plates under the ocean are converging that could lead to a nine or higher on the Richter scale. New Madrid, Missouri is on an unstable fault which is likely to rupture again and hit St. Louis hard. And even Boston is being warned to take precautions as there is more than a 50 percent chance of a 6.3 quake in the next 200 years u