On August 1, 1966, a 25-year-old man rode an elevator to the top floor of the University of Texas Tower and began shooting at the people below. The attack, which left more than a dozen dead and many more injured, remains among America’s most infamous mass murderers.

Director Keith Maitland’s new film Tower combines archival footage and rotoscope animation to detail the events of that terrible day. The film is executive-produced by Meredith Vieira and Luke Wilson.

Tower opens in New York on Wednesday at the Film Forum and in Los Angeles on Friday at the Laemmle Royal.

Read an interview with Maitland here, see an exclusive clip from the film above, and watch the trailer below.