The game again sparked controversy in the United States when it was found that Eric Harris and Dylan Klebold, who committed the Columbine High School massacre on April 20, 1999, were avid players of the game. While planning for the massacre, Harris said in his journal that the killing would be "like playing "Doom"", and "it'll be like the LA riots, the Oklahoma bombing, World War II, Vietnam, "Duke Nukem" and "Doom" all mixed together", and that his shotgun was "straight out of the game". A rumor spread afterwards that Harris had designed a "Doom" level that looked like the high school, populated with representations of Harris's classmates and teachers, and that he practiced for the shootings by playing the level repeatedly. Although Harris did design custom "Doom" levels (which later became known as the "Harris levels"), none have been found to be based on Columbine High School.