On this day in 1999, two teenage gunmen kill 13 people in a shooting spree at Columbine High School in Littleton, Colorado, south of Denver. At approximately 11:19 a.m., Dylan Klebold, 18, and Eric Harris, 17, dressed in trench coats, began shooting students outside the school before moving inside to continue their rampage. By 11:35 a.m., Klebold and Harris had killed 12 fellow students and a teacher and wounded another 23 people. Shortly after noon, the two teens turned their guns on themselves and committed suicide.
The crime was the worst school shooting in U.S. history (until 33 people, including the gunman, were killed in the Virginia Tech shooting on 16 April 2007) and prompted a national debate on gun control and school safety, as well as a major investigation to determine what motivated the teen gunmen. In the days immediately following the shootings, it was speculated that Klebold and Harris purposely chose jocks, minorities and Christians as their victims. It was initially reported that one student, Cassie Bernall, was allegedly asked by one of the gunmen if she believed in God. When Bernall said, "Yes," she was shot to death. Her parents later wrote a book titled ‘She Said Yes’, honouring their martyred daughter. Apparently, however, the question was not actually posed to Bernall but to another student who had already been wounded by a gunshot. When that victim replied, "Yes," the shooter walked away.
Subsequent investigations also determined that Harris and Klebold chose their victims randomly. Their original plan was for two propane bombs to explode in the school's cafeteria, potentially killing hundreds of people and forcing the survivors outside and into the gunmen's line of fire. When the bombs didn't work, Harris and Klebold went into the school to carry out their murderous rampage.
There was speculation that Harris and Klebold committed the killings because they were members of a group of social outcasts called the "Trenchcoat Mafia" that was fascinated by goth culture. Violent video games and music were also blamed for influencing the killers. However, none of these theories was ever proven.
Columbine High School reopened in the fall of 1999, but the massacre left a scar on the Littleton community. Mark Manes, the man who sold a gun to Harris and bought him 100 rounds of ammunition the day before the murders, was sentenced to six years in prison.
In the aftermath of the Columbine shootings, many schools enacted "zero tolerance" rules regarding disruptive behaviour and threats of violence from students.