Try reading your Bible rather then skiming the highlights.
In the case of the flood there was only one good person left on earth. In the case of Sodom and Gomorrah there were not 10 good left in the whole valley.
I know for a fact there were a LOT more then 10 good in NO.
Try this verse instead, "It rains on the just and the unjust."
This is why we can't determine for sure if the wrath of God has been visited on New Orleans. However, anyone who arrogantly rejects the Bible and the God who wrote it is shortsighted and foolish. At the very least, natural disasters teach us that this life and its material pleasures are oh, so temporary, but human relationships are precious. The Bible says the only thing that is truly long-lasting is love of God and our fellow man.