Eric Harris and Dylan Klebold, armed with guns and homemade explosives, attacked Columbine High School, killing 13 people and wounding 21 before dying by suicide. The massacre, then the deadliest school shooting in U.S. history, became a grim national reference point, reshaping school security policy and dominating American debates over gun violence, bullying, and media coverage for years afterward.
Shortly before 11:20 a.m., Eric Harris and Dylan Klebold, both seniors, walked into Columbine High School carrying two sawed-off shotguns, a rifle, a pistol, and dozens of homemade explosive devices, many of which failed to detonate as planned in the cafeteria. Their original plan, a mass bombing meant to kill hundreds, largely failed mechanically, leaving them to carry out a shooting rampage through hallways and the library instead.
Over about 49 minutes, they killed 12 students and teacher Dave Sanders and wounded 21 more before turning their guns on themselves in the library. Police response was criticized afterward for its caution, as SWAT teams took hours to fully clear the building, a delay that reshaped active-shooter protocols nationwide toward immediate entry.
Columbine became a cultural fault line, spawning intense scrutiny of video games, goth subculture, bullying, and gun access, much of it later found to be based on misconceptions about the killers' motives and social standing. It also launched the modern era of school lockdown drills and armed campus security, a landscape now familiar to generations of American students who came after.
Key people: Eric Harris, Dylan Klebold