LANSA Flight 502 was a Lockheed L-188A Electra operated by Líneas Aéreas Nacionales Sociedad Anónima (LANSA) which crashed shortly after takeoff from Quispiquilla Airport near Cusco, Peru, on August 9, 1970, after losing all power from one of its engines. The four-engine turboprop aircraft, registered OB-R-939, was bound from Cusco to Lima, carrying 8 crew and 92 passengers. All but one of the occupants died from injuries sustained from impact forces and post crash fire. Two people on the ground were also killed. There were 49 American high school exchange students on board, all of whom perished. A Peruvian government investigation concluded that the accident was caused by improper execution of engine-out procedures by the flight crew, aggravated by lack of maintenance and overloading. LANSA was fined and its operations were suspended for 90 days. At the time, the crash was the deadliest ever in Peruvian history.