The Columbine High School massacre was a school shooting which occurred on April 20, 1999, at Columbine High School in Columbine, an unincorporated area of Jefferson County in the State of Colorado. Two senior students, Eric Harris and Dylan Klebold, murdered a total of 12 students and one teacher. They injured 21 additional students, with three other people being injured while attempting to escape the school. The pair then committed suicide.