<Tr> <Th> Injured </Th> <Td> 24 (combined total) </Td> </Tr> <Tr> <Th> Weapons </Th> <Td> Intratec TEC - DC9, Stevens 311D double barreled sawed - off shotgun, explosives and two knives </Td> </Tr> <P> Eric David Harris (April 9, 1981--April 20, 1999) and Dylan Bennet Klebold (/ ˈkliːboʊld /; September 11, 1981--April 20, 1999) were two American mass murderers who killed 13 people and wounded 24 others armed with firearms and knives on April 20, 1999, at Columbine High School in Columbine, Colorado . They were twelfth grade (senior) students at the high school . The shooting rampage came to be known as the Columbine High School massacre . Harris and Klebold committed suicide in the library, where they had killed 10 of their victims . </P> <P> Harris was born in Wichita, Kansas . The Harris family relocated often, as Eric's father, Wayne Harris, was a U.S. Air Force transport pilot . His mother, Katherine Ann Poole, was a homemaker . The family moved from Plattsburgh, New York, to Littleton, Colorado, in July 1993, when Wayne Harris retired from military service . </P>

What grade were eric harris and dylan klebold in