AP Photo

Claude Prépetit had seen it coming in his figures. He had done the calculations, in millimeters and in centuries, he had calculated the pressure that was building up beneath his feet, and he had estimated the energy that would eventually be discharged. And when the earth finally did shake, and falling concrete ceilings, stone walls and wooden beams killed at least 170,000 people within the space of 40 seconds, that was when Prépetit thought to himself: "This is it -- this has to be a seven."