April 16, 2007: Virginia Tech

April 16, 2007: Seung-Hui Cho, 23, fatally shot 32 people in a dorm and a classroom at Virginia Tech in Blacksburg, then killed himself. Pictured: Virginia Tech senior Angela Lucero (L) and Mary O' Mara battle tears at a memorial service on the field of the football stadium to honor the victims, April 17, 2007 in Blacksburg, Virginia

Credit: Photo by Scott Olson/Getty Images