We will be admonished not to make politics out of tragedy, but we have a responsibility to figure out what went wrong with the response to Hurricane Katrina.
Today, far too often, tragedy is employed as an incantation to ward off responsibility. (Try Googling the phrase, "The events of today were tragic, but ..." to get a taste of what I mean.)
Tragedy is an idea we get from the Greeks -- human life as a grand, hopeless struggle against our own flaws and unloving celestial forces that conspire to bring us down. Tragedy is a spectacle, provoking a catharsis composed, in Aristotle's phrase, of "pity and terror" in the spectator -- but not outrage. To call something tragic is to take a stance of elegiac distance. The world view that produced the idea of tragedy also produced great thinkers and artists, but it did not produce prophets.