About 900 Columbine High School students head in to the cafeteria for lunch or hit the books in the library or in classrooms. A 911 dispatcher receives the first report that gun shots had been fired at Columbine High School. According to investigators, Eric Harris and Dylan Klebold move from the student parking lot into the cafeteria and upstairs to the library. The last shots are fired, ending a 15-minute reign of terror. Noon Police SWAT teams find several explosive devices around the school.
Ambulances take the first wounded students, all of whom managed to run outside, to area hospitals.
According to investigators, Harris and Klebold commit suicide. Early afternoon 615 officers from 27 agencies converge on the school. Anguished parents, awaiting word on their children, gather at nearby Leawood Elementary School. 4 p.m. The sheriff's spokesman confirms that as many as 25 people are dead. Officers find the bodies of both suspects.