In the mid-1980s Yale University sociology professor Charles Perrow penned a highly influential book by the provocative title of Normal Accidents. In it Perrow argues that the dizzying complexity of much of modern technology, when matched with

what he calls "tight coupling"-meaning processes happen fast and cannot easily be turned off-can inevitably lead to catastrophes. Nuclear power, Perrow notes, is especially vulnerable to such "system" or "normal" accidents. Moreover, piling on more and more safety features is not necessarily a solution because they add to the complexity, often in ways that are difficult to predict. Companies in such catastrophe-prone industries can train operators till they drop, Perrow says, but accidents will still happen.

Destined for Disaster

Formal accident investigations usually start with an assumption that the operator must have failed, and if this attribution can be made, that is the end of...