Perrow, developer of normal accident theory, argues here that we must reduce the size of targets that are vulnerable to disasters because organizations, including political ones, cannot completely prevent all the risks associated with the potential disasters that a society might face. A basic tenant of Perrow’s argument is that disasters must be viewed as a normal part of our existence, for tornadoes, floods, hurricanes, earthquakes, forest fires, and even terrorists attacks, among many others, cannot be easily removed from the human environment. Perrow argues that the primary method of reducing our vulnerabilities to these inevitable disruptions is not to put a band-aide on them with simple remedies associated with prevention, remediation, and damage limitation, but to limit to the greatest degree possible, the potential damage that can be done by a devastating event. To complete this task, Perrow recommends dealing with the three major source-targets open to the most widespread devastation: 1) concentration of energy (explosive gases, toxic substances, diseased woods, and brush); 2) concentrations of populations that might be mixed with high energy concentrations; and 3) concentrations of economic and political power. Working in these three areas would have the highest payoff in reducing infrastructure damage and human casualties. The idea outlined in this book, that of reducing vulnerability to inevitable disasters, may be helpful to the managers of high risk organizations who are responsible for preventing and responding to disasters.