Feb. 14, 2008: Northern Illinois University

Feb. 14, 2008: Former student Steven Kazmierczak, 27, opened fire in a lecture hall at Northern Illinois University in DeKalb, Ill., fatally shooting five students and wounding 18 others before committing suicide. Pictured: Five crosses representing the five victims are seen at the campus of Northern Illinois University in DeKalb, Illinois, on February 15, 2008.

Credit: Amanda Rivkin/AFP/Getty Images