Judgement on a 'wicked' city?

The Katrina disaster, according to some fundamentalist Christians, was God's judgement on a wicked city. I find that difficult to believe on several levels, the first being that Alabama took quite a hit too. Alabama wasn't preparing to have a 'gay mardi gras' parade that I know of. Natural disasters happen. To suggest that the many thousands of victims 'deserved' their fate is unbelievable. It is also a terrible way to view God's love.

If the claims are true, then what evil deeds were the victims of the Tsunami in Southeast Asia poised to commit? And why are cities like Rio de Janeiro still above water when Carnival celebrations are tolerated year after year?

If New Orleans is a 'wicked city,' how many more wicked cities didn't get deluged by Katrina? Why would God single out just one for judgement? If to make an example, a big city of rich white people might make a better statement and better 'press' for it seems many don't care for the many thousands of poor black people. Another question comes to my mind. I wonder how many of those victims are Christians?

I have no claim to know the mind of God. The bible says no one knows the mind of God, but simple logic tells me he would not operate that way. In the old testament, when God brought judgement upon a people, he gave plenty of warning and took credit for it (through his prophets). Thus, until God speaks, I believe it was a 'natural' disaster, not a supernatural one.