The Ribbon Creek incident occurred on the night of April 8, 1956, when Staff Sergeant Matthew McKeon, a junior drill instructor at the Marine Corps Recruit Depot Parris Island, South Carolina, marched his assigned platoon into Ribbon Creek, a swampy tidal creek. The incident resulted in the deaths of six United States Marine Corps recruits. McKeon was found guilty of possession and drinking alcohol on duty and of negligent homicide.