273 : On May 25 , 1979 , American Airlines Flight 191 , a McDonnell Douglas DC-10-10 , crashed shortly after lifting off the runway at Chicago O'Hare Airport after the number one ( left ) engine and pylon separated from the wing . This broke hydraulic lines , causing leading edge lift devices to retract on that side of the aircraft and resulted in asymmetrical lift and loss of control . The accident was attributed to improper maintenance procedures . The crash resulted in the deaths of all 271 passengers and crew on board , as well as two people on the ground . It remains the deadliest commercial aircraft accident in United States history , and was also the country 's deadliest aviation disaster until the September 11 attacks in 2001
American Airlines Flight 191
American Airlines Flight 191
Aviation accidents and incidents