UPPER DARBY, Pa. (AP) -- Six teenagers are facing charges stemming from a fight in their suburban Philadelphia high school during which a teacher was knocked unconscious. The melee was caught on video at Upper Darby High School on Oct. 8, when police say two groups of students began fighting outside the school cafeteria. Authorities said a 30-year-old teacher trying to break up the fight was punched, knocked to the ground and jumped on, suffering a concussion and torn ligaments to his left leg. Police announced the arrests Thursday of six students who were among dozens involved in the fight. The only suspect being identified is 18-year-old Jermaine Richardson, who police say assaulted the teacher. The other five suspects are minors -- a 14-year- old, two 16-year-olds and two 17-year-olds -- and face juvenile charges.