On 20 April 1999 , Eric Harris and Dylan Klebold killed 12 students , a teacher , and themselves in the Columbine High School massacre . The two were allegedly obsessed with the video game '' Doom '' . Harris also created WADs for the game , and created a large mod named " Tier " which he called his " life 's work " . Contrary to rumor , however , neither student had made a '' Doom '' level mimicking the school 's layout , and there is no evidence the pair practiced the massacre in '' Doom ''
Columbine High School massacre
Columbine High School massacre
Video game controversies