If there is an organizing theme in sociology, it is social order: what it looks like, how to think about the various forms it takes, and how to explain it. Conversely, what happens when social order breaks down? What changes are wrought in how people see the world, and most important, what is altered in how they relate to one another when social order goes awry? The study of risk, danger, and catastrophe is a special case of the larger field of social breakdown.

Sociologists have long been interested in phenomena that harm people and what people value. Until recently, most of this work concentrated on harm from natural events such as earthquakes, floods, and tornadoes, but many researchers now write about "technical" or "technological" risks. In some ways the distinction between natural and technological risks or disasters is not helpful: There...