a school shooting and attempted bombing occurred on april 20,1999, at columbine high school in columbine, colorado, united states . The perpetrators, twelfth-grade students Eric Harris and Dylan Klebold, murdered twelve students and one teacher; ten were killed in the school library, where Harris and Klebold subsequently died by suicide.
Twenty-one additional people were injured by gunshots, and gunfire was exchanged with the police. Another three people were injured trying to escape. The Columbine massacre was the deadliest mass shooting at a K-12 school in U.S. history until December 2012.
It is still considered one of the most infamous massacres in the U.S. for inspiring many other school shootings and bombings; the word “Columbine” has since become a byword for modern school shootings.
As of 2025, Columbine is still the deadliest school shooting in Colorado, the deadliest high school shooting in the United States to happen west of the Mississippi River, and one of the deadliest mass shootings in the United States.
Harris and Klebold, who planned for roughly a year, and hoped to have a large number of victims, intended for the attack to primarily be a bombing and only secondarily a shooting.
However, the pair chose to launch a shooting attack after the several homemade bombs they planted in the school failed to detonate.Their motive remains inconclusive.
