The Columbine High School Massacre
On April 20, 1999, seniors Eric Harris and Dylan Klebold arrived at Columbine High School in Littleton, Colorado, armed with two shotguns, a semiautomatic rifle, a handgun, and dozens of improvised bombs. They killed 12 students and one teacher and wounded 21 others before dying by suicide in the school library. The massacre was the deadliest school shooting in American history at the time and permanently altered how the country thought about school safety, bullying, and teenage violence.
The attack had been extensively planned over more than a year. Harris and Klebold had intended to detonate two large propane bombs in the school cafeteria during lunch — which would have killed hundreds — but the bombs failed to detonate. The gunfire that followed was intended as a secondary phase of an attack designed for mass casualties far exceeding what occurred. Journals, videos, and writings left by both killers were analyzed exhaustively in the years after the shooting.
The immediate aftermath produced a wave of incorrect narratives — that Harris and Klebold were bullied outcasts targeting athletes, that they were members of a "Trenchcoat Mafia," that they were inspired by Marilyn Manson or violent video games. These narratives were progressively dismantled by later research. Psychologist Peter Langman and FBI profilers concluded Harris was a clinical psychopath and Klebold a deeply depressed follower, and that the attack was motivated by fantasies of superiority and revenge rather than victimhood.
Columbine transformed American school security infrastructure nationwide, leading to locked doors, security cameras, active shooter drills, and zero-tolerance policies. It also inadvertently inspired a wave of copycat planners who studied the attack in detail. The families of victims have spent decades advocating for gun control measures. The school was extensively renovated in 1999 to remove the crime scene environment. Columbine remains the reference point against which every subsequent school shooting in the United States is measured.