It does not cost much to have inspectors make sure that building are built correctly in places where there are rules on the building....or to put the rules in. On a couple news shows they showed aerial views of the steep side of a hall...every structure was leveled. Hard to tell from the air, but it looked like the structures may have been thrown off of the hill by ground motion rather than landslide...such a situation would be hard to build for...I think you would have this happen (and it did in Santa Cruz Mountains and even distant from Northridge) in California....
Chris