American Airlines Flight 191 was a regularly scheduled passenger flight in the United States from O'Hare International Airport in Chicago, Illinois, to Los Angeles International Airport. On May 25, 1979, the McDonnell Douglas DC-10-10 operating the route crashed moments after takeoff from Chicago. All 258 passengers and 13 crew on board were killed, along with two persons on the ground. The accident remains the deadliest airliner accident to occur on United States soil. Investigators found that as the jet was beginning its takeoff rotation, engine number one on the left (port) wing separated and flipped over the top of the wing. As the engine separated from the aircraft, it severed hydraulic fluid lines and damaged the left wing, resulting in a retraction of the slats. As the jet attempted to climb, the left wing aerodynamically stalled while the right wing, with its slats still deployed, continued to produce lift. The jetliner subsequently rolled to the left and reached a bank angle of 112 degrees (partially inverted), before impacting in an open field near a trailer park located near the end of the runway. The engine separation was attributed to damage to the pylon rigging structure holding the engine to the wing caused by inadequate maintenance procedures at American Airlines. While maintenance issues and not the actual design of the aircraft would ultimately be found responsible for the crash, the accident and subsequent grounding of all DC-10s by the Federal Aviation Administration added to an already negative perception of the jet in the eyes of the public caused by other unrelated accidents.