And the entire Midwest, inundated every year, not just occasionally, with deadly tornados. Malaria was a problem in New Orleans until DDT came along, now that's the problem. California has not just earth quakes, wild fires, mud slides it also is hit with crippling drought. I would not live at the base of a CA coastal foothill (soil structure famous for giving way when saturated), or in a tight wooded canyon, but avoiding risk entirely is difficult. The best one can do is prioritize and try to make reasonable choices. I agree that in a sane and just world responsible social policy would forbid building on questionable land. A world run by elephants, maybe.