A entire 757... The agent said they would not preboard elites since everyone was a elite. Of course not a single person listened and they all tried to board after F class was called. We had to get two police officers to help us, one on the plane and one at the top. It really was sad to see, and it took over an hour to board the plane. Also, after about 40 people were in the back we had to check all roller boards.