Disasters have a structure. They self-organize and “pessimize” the production of damage. In response, society develops technology at the interface between nature and society. The cost of earthquake disasters has been rising exponentially since the 1960s, when probabilistic seismic hazard assessment began to be introduced. Why is it so difficult to learn from disasters? A rational strategy of disaster prevention must be based on better science, meaning disaster physics as well as social science. The principles involved are different. Disaster physics is based on the maximum entropy principle. Social disaster science is based on a principle of least resistance. For example, poor designs survive because it is easier to blame the operators, or the government. Plate-boundary disasters occur because the hazard is high; intraplate disasters occur because it is low. In both cases, the entropy is maximized. Examples of recent disasters are discussed.