Answer:
Los Angeles, California, rests on a major (and active) fault line known as the San Andreas Fault. It's the line between the Pacific and North American tectonic plates, and more seismic activity is measured daily than on the New Madrid Fault, which runs through New Madrid, Missouri, and around the mid-west. Chicago is still at risk, of course, but not nearly as much, given the small activity of the fault line.
