Can my college turn me down if I've already been accepted?

I've been accepted to a pretty good public college. I've already received my schedule and paid the deposit and everything. I've also just received my high school diploma and passed all of my classes. Is there any possibility that they can turn me down? I'm asking this because I've also told another college that was my back up school that I would be attending the back up school and their orientation is tomorrow but, I don't want to go since I won't be attending that school unless I somehow get turned down from the school I want to go to. Hopefully that makes sense....