Human inhumanity to man has been around as long as humans have existed.
Why 9/12? Why not when the Rowandans massacred each other? Why not Bosnia? Why not Somolia? Why not the African AIDS statistics?
One of the problems with the concept of a good and caring God is why He permits suffering to happen. Every church has wrestled with this problem (and none really successfully answer it.)
What was it about 6000+ New Yorkers dying at the hands of a couple dozen fanatics that did it for you?
I say that not as a card-carrying Christian, but as one who is cynical about most (OK, all the ones I'm familiar with) major religions. If there is an afterlife, I think it'll be more like Spider Robinson's Life House rather than clouds, 70 virgins, and/or choirs of angels. But if you *are* a believer, nothing that happened on 9/11/2001 should turn you one way or the other. Senseless events have happened before and will happen again.