As an American Airlines DC-10 jet roared into the sky over O'Hare International Airport on this Friday afternoon, its left engine fell off. Flight 191, bound for Los Angeles at the beginning of the Memorial Day weekend, rolled over in the air and plunged to the earth less than a mile from the runway. The plane "burst into a pillar of flame and smoke that could be seen up to eight miles away," the Tribune reported. Nearby resident Abe Marmel, who was working in his vegetable garden, heard the explosion: "By the time I looked up, there was a rain of fire falling down on me."

All 271 people on board and two people on the ground were killed. It remains America's worst aviation disaster. The death toll could have been higher, but the plane just missed hitting a trailer park north of the airport. A priest at a Catholic church in Elk Grove Village reached the scene within minutes."It was too hot to really do anything but administer the last rites," he told the Tribune. "I just walked around trying to touch a body here or there, but I could not. It was too hot to touch anybody, and I really could not tell if they were men or women. Bodies were scattered all over the field." An assistant state's attorney said he saw "kiddie books and briefcases and business papers strewn all over the place. And a child's book titled `The Beginning of Life.' "

As the nation's commercial aviation center, Chicago had been the scene of more than its share of air tragedies, beginning in 1940, when a United Airlines DC-3 laden with ice crashed while trying to land at Municipal (later Midway) Airport, killing 10 people.

One disaster had a bizarre twist: Among the 45 people killed in the 1972 crash of a United 737 near Midway was Dorothy Hunt, wife of E. Howard Hunt, one of the conspirators in the Watergate break-in. After it was discovered that she had been carrying a briefcase containing $10,000 in cash (later linked to the scandal), some convoluted sabotage theories surfaced. But the accident was blamed on pilot error.

In the investigation following the Flight 191 disaster, the National Transportation Safety Board found that mechanics in Tulsa had taken a shortcut in removing the engines from the plane's wing pylons for maintenance. That mistake two months before the crash had cracked an aluminum component in the pylon. Wear and tear widened the crack until the piece broke, and as the engine tore loose, it damaged electrical and hydraulic systems, a combination that left the plane unable to fly. When the DC-10 was certified for service 11 years earlier, engineers calculated the odds of such a simultaneous failure at 10 billion to 1.