Pierce Street and began shooting at students and staff. on Tuesday morning, Dylan Klebold, 17, and Eric Harris, 18, entered Columbine High School off of S.
The tragic annihilation is considered one the worst mass shootings in U.S. On April 20, 1999, two Colorado teens walked into Columbine High School in Littleton, where they fatally shot 13 people and injured over 20 others before turning the guns on themselves, ending their own lives.