What Would Drive These People to Do It?

I've often heard about september 11th, about how the U.S. would never really recover, but every time I hear that, I wonder, why did those people in the plane do that, what motivated them to sacrifice there lives to kill many others? There is the customary answer "they where crazy terroists", but I think there is something else. They didn't drop bombs, they dropped themselves, when people are willing to kill themselves to make a point, they must really want it to get through. …