Columbine High School massacre
school shooting at Columbine High School in Columbine, Colorado, United States on April 20, 1999
On April 20, 1999, high school senior students Eric Harris and Dylan Klebold murdered 13 students and one teacher in a school shooting and attempted bombing at Columbine High School in Columbine, Colorado, United States. Twenty people were injured by the gunfire, and three others were injured while trying to escape. The attack ended when Harris and Klebold committed suicide. The Columbine massacre was the deadliest mass shooting at a K–12 school in U.S. history until December 2012. It was also the deadliest high school shooting until Parkland high school in 2018. Columbine is considered among the most infamous massacres in the United States, which as of June 2025, had inspired more than 70 copycat crimes, a phenomenon dubbed the Columbine effect, and Columbine has become a byword for modern school shootings.
Harris and Klebold, who planned for roughly a year, intended the attack to be primarily a bombing and only secondarily a shooting. The pair launched a shooting attack after the homemade bombs they planted in the school failed to detonate. Their motive remains uncertain. The police were slow to enter the school and were strongly criticized for not intervening during the shooting.
The public source identifies “Columbine High School massacre” as school shooting at Columbine High School in Columbine, Colorado, United States on April 20, 1999. This brief keeps that definition visible, then builds a research path around Columbine, High and School.
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A short description can identify a subject without explaining its stakes. For “Columbine High School massacre”, the useful work is to connect “school shooting at Columbine High School in Columbine, Colorado, United States on April 20, 1999” to the records capable of establishing context and consequence.
Contemporary correspondence, administrative files and participant testimony can test how later narratives organized the event or institution. The source revision retrieved here is dated Sep 22, 2026. The linked authority identifier is Q473845. The Library of Congress control number is sh2007004696. Authority coordinates are 39.603, -105.075. 2 of 2 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank. The first chronological checks are 1999, 2012, 2018 and 2025.
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This entry incorporates text from “Columbine High School massacre” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.