Saturday marks the 20th anniversary of the mass shooting at Columbine High School.
13 people were shot and killed in Littleton, Colorado on April 20, 1999; 12 students and a teacher.
It’s still remembered as one of the deadliest mass shootings in American history. Two students from the school opened fire on their classmates before taking their own lives.
A vigil was held in Littleton on Friday night to remember the victims. On Saturday, the community marked the somber anniversary with service projects and a remembrance ceremony.