Fifty for 150: Columbine High School is site of mass shooting in 1999

The massacre at Columbine High School on Aug. 20, 1999, became the largest school shooting in U.S. history at the time. It left 12 students, one teacher and both gunmen dead. 

This story is part of Colorado at 150. Each Fifty for 150 story focuses on an event that helped define Colorado over 150 years of statehood. Newsline is publishing one Fifty for 150 story every weekday in reverse chronological order until the sesquicentennial, Aug. 1, when the final of 50 stories, about the declaration of statehood, will appear.

The shooting in Littleton was one of the first school shootings to be broadcast live on national television, making Columbine infamous across the U.S. 

The 13 people who were killed at Columbine were: Cassie Bernall, 17; Steven Curnow, 14; Corey DePooter, 17; Kelly Fleming, 16; Matthew Kechter, 16; Daniel Mauser, 15; Daniel Rohrbough, 15; William “Dave” Sanders, 47; Rachel Scott, 17; Isaiah Shoels, 18; John Tomlin, 16; Lauren Townsend, 18; and Kyle Velasquez, 16. 

Additionally, 24 people in the school were injured. 

The two shooters, Eric Harris, 18, and Dylan Klebold, 17, made home videos explaining their plans and apologizing to their parents. 

School shootings and gun violence have increased drastically since Columbine. Columbine has influenced the actions of many other school assailants, including the Sandy Hook Elementary shooter, who killed 20 children and six adults in 2012.

Anne Marie Hochhalter, who was a 17-year-old junior when the shooters shot and paralyzed her, died in 2025. The Jefferson County Coroner’s Office deemed her death a homicide, because the two gunshot wounds that paralyzed her were a “significant contributing factor” in her death. 

Each year on April 20, the high school hosts a Columbine Day of Service, inviting community members, students, families and teachers across Colorado to participate in “service and gratitude” to honor the lives lost in the shooting. Colorado Gov. Jared Polis in 2019 issued a proclamation making April 20 an annual day of service and recommitment in the state. 

A memorial in the nearby Clement Park pays tribute to the victims and the survivors of Columbine. 

Families of many of the victims as well as survivors have advocated gun regulations and an end to gun violence in the years since the shooting. 

Tom Mauser, whose son Daniel died in the shooting, spoke at a protest on May 1, 1999, against the National Rifle Association holding its national convention in Denver. He held a sign that said, “My son Daniel died at Columbine. He’d expect me to be here today.” Mauser has spoken out against gun violence and in support of gun legislation for more than two decades since his son died and published a book in 2012. 

Dozens of gun violence prevention laws have passed in Colorado since Columbine, and several other mass shootings have devastated the state. A gunman shot and killed 12 people at a movie theater in Aurora in 2012. Another killed 12 people at a King Soopers in Boulder in 2021. In 2022, a shooter killed five people at a LGBTQ+ nightclub in Colorado Springs. Most recently, a student shot and injured two others at Evergreen High School in Jefferson County before killing himself in September.