“Interms of natural domestic disasters, we've never seen anything quitelike Katrina,” said Barry A. Hong, Ph.D., professor and vice chair ofpsychiatry at Washington University, St. Louis. Up to this point, mostdomestic disasters, including Sept. 11, were confined to a discretegeographical area such as part of a city or a state—not covering anentire city like New Orleans.

Inaddition, Katrina's devastating blows came in stages. “In some sense,you almost have a cascade of disasters—the hurricane was one, theflooding was [another], and the relief efforts were [yet another]disaster themselves, as was the forced relocation of people,” he said.“We could separate all those, and in the past they were all disastrousthings, but not tied into a cascading sequence of disasters.”