United Airlines Flight 232 (UA232) (UAL232) was a regularly scheduled United Airlines flight from Stapleton International Airport in Denver to O'Hare International Airport in Chicago, continuing to Philadelphia International Airport. On July 19, 1989, the DC-10 serving the flight crash-landed at Sioux Gateway Airport in Sioux City, Iowa, after suffering a catastrophic failure of its tail-mounted engine due to an unnoticed manufacturing defect in the engine's fan disk, which resulted in the loss of all flight controls. Of the 296 passengers and crew on board, 112 died during the accident, while 184 people survived. 13 passengers were uninjured. It was the deadliest single-aircraft accident in the history of United Airlines.