New Orleans Mayor Ray Nagin in this radio interview (transcript) about one cause of the looting:
And one of the things people -- nobody's talked about this. Drugs flowed in and out of New Orleans and the surrounding metropolitan area so freely it was scary to me, and that's why we were having the escalation in murders. People don't want to talk about this, but I'm going to talk about it.
You have drug addicts that are now walking around this city looking for a fix, and that's the reason why they were breaking in hospitals and drugstores. They're looking for something to take the edge off of their jones, if you will.
And right now, they don't have anything to take the edge off. And they've probably found guns. So what you're seeing is drug-starving crazy addicts, drug addicts, that are wrecking havoc. And we don't have the manpower to adequately deal with it. We can only target certain sections of the city and form a perimeter around them and hope to God that we're not overrun.