During takeoff from O'Hare International Airport in Chicago, an engine detached from American Airlines Flight 191, causing a crash that killed 273 people in the deadliest aviation accident in United States history.

Chicago O'Hare International Airport is the primary international airport serving Chicago, Illinois, United States, located on the city's Northwest Side, approximately 17 miles (27 km) northwest of the Loop business district. The airport is operated by the Chicago Department of Aviation and covering 7,627 acres. O'Hare has non-stop flights to 249 destinations in North America, South America, the Caribbean, Europe, Africa, Asia, the Middle East and the North Atlantic region as of Summer 2024. As of 2024, O'Hare is considered the most connected airport in the United States, and fifth most connected airport in the world. It is also the world's fourth busiest airport and 16th largest airport.

American Airlines Flight 191 was a regularly scheduled domestic passenger flight from O'Hare International Airport in Chicago to Los Angeles International Airport. On the afternoon of May 25, 1979, the McDonnell Douglas DC-10 operating this flight was taking off from runway 32R at O'Hare International when its left engine detached from the wing, causing a loss of control. The aircraft crashed about 4,600 feet (1,400 m) from the end of runway 32R. All 271 occupants on board were killed on impact, along with two people on the ground. With a total of 273 fatalities, the disaster is the deadliest aviation accident to have occurred in the United States.