Assume that there exist two people, person A and person B. Person B is falling into a black hole. I understand that due to relativity and time dilation, person A will have to spend an infinite amount of time to watch person B cross the event horizon. Person B will appear to move at a slower and slower rate towards the event horizon. (I know that person B will be gravitationally red shifted). So is it true, that relative to us in our universe, nothing ever falls into a black hole? If this is true, how is it possible that black holes ever form in the first place?