The special effects are so extensive that it amplifies their unreality. The movie is more concerned with the individual windows exploding out of the buildings than it is about the underlying mechanics of what is actually happening. It is preposterous enough that the professor not only predicts the second quake but hacks into the television networks. Wi-fi, electricity and broadcast channels are still operating, apparently, which is a long shot, but also people are actually watching the television news to find out what is happening, which is even more unlikely. And then, odds fast plummeting below zero, San Francisco is evacuated in a pretty orderly fashion (some folks stopping to loot flat-screens — why it it always flat-screens?), presumably so we can relish all the destruction without worrying too much about the people, the opposite of the neutron bomb. This is PG-13 “action violence,” designed to be exciting, not terrifying.