 How could this possibly happen? How could this be such a failure? Yeah, that was the only thing that's going through my mind for the last 48 hours. It just didn't make any sense to me. And it still doesn't make sense to me how they allowed this to happen at all. One person in the crowd was killed, two others critically injured. Do you feel like somebody let you down? Absolutely. Absolutely. Scott McFarlane, CBS News, Butler, Pennsylvania.