'Tower' Recalls A Time When Mass School Shootings Weren't So Routine

If mass school shootings seem commonplace in 2016, they were anything but in 1966, when a student killed 17 people and injured 31 at the University of Texas-Austin. It remained the first and deadliest campus massacre in the United States until the Virginia Tech carnage in 2007.

Fifty years later, the new documentary "Tower," which premiered at South by Southwest on Sunday, blends archival footage and rotoscope animation (think "A Scanner Darkly") to re-create the harrowing 96-minute standoff from the perspective of survivors who witnessed it. The Huffington Post has an exclusive clip that showcases the movie's technique, as well as a new poster, both of which promise unprecedented insight into a violent episode that has since become all too normal.