Before Columbine, before Newtown and before Virginia Tech, there was the University of Texas. Fifty years ago, a man with a half dozen guns climbed to the 27th floor of the clock tower at the University of Texas at Austin. Just before the bell in the tower marked the noon hour, he began shooting. Over the next hour and a half, he killed more than a dozen people and an unborn baby, and wounded 32 others. A new documentary takes us back to that afternoon in Austin and tells the story through the people who survived the massacre. It’s called Tower.