<a href="http://www.cnn.com/SPECIALS/2007/virginiatech.shootings/" target="_blank">Virginia Tech</a> student Seung-Hui Cho went on a shooting spree on the school's campus in April 2007. Cho killed two people at the West Ambler Johnston dormitory and, after chaining the doors closed, killed another 30 at Norris Hall, home to the Engineering Science and Mechanics Department. He wounded an additional 17 people before killing himself.