American Airlines Flight 191

American Airlines Flight 191 was a scheduled commercial flight from O'Hare International Airport in Chicago to Los Angeles International Airport. The aircraft used was a McDonnell Douglas DC-10-10. On May 25, 1979, the aircraft crashed into an open field in Des Plaines, Illinois. All 271 people (258 passengers and 13 crew) on the flight were killed. Two people on the ground were killed and five others were hurt. The crash was caused by the loss of one of the engines, which caused damage to the left wing. The loss of the engine happened because of bad maintenance to the aircraft that had been done eight weeks before the crash. It is the worst plane crash to happen in the United States.
Airplane involved.
The airplane that crashed was a McDonnell Douglas DC-10-10, tail number N110AA. It was delivered new to American Airlines after its first flight in 1972, and at time of accident it has flown for 19871 hours. It was powered by 3 General Electric CF6-6D engines.
Accident.
The plane, which just arrived from Phoenix, was assigned to fly Flight 191 from Chicago to Los Angeles. At 2.59pm (local time GMT-6), the plane began its taxi to Runway 32R, and at 3.02pm was cleared to takeoff. However, as First Officer Dillard began to rotate, the number one engine, broke off from its pylon on the left wing. With the remaining length of the runway, stopping the plane would be impossible, so the pilots continued with the takeoff, knowing that two engines are enough to fly a DC-10, but not knowing that the engine had completely separated from the aircraft..
Shortly after the engine broke off, the plane began a stabilized, steep climb to 300 ft. The left wing's leading edge slats then retracted, raising that wing's stall speed from 124 knots to 159 knots. The DC-10, travelling at V2 speed (153 knots) then uncontrollably began to roll to the left, as the pilots tried to control the aircraft. The plane reached a maximum bank angle value of 112 degrees left as the nose dropped through 20 degrees below the horizon, and the airplane crashed into an open field in front of an aircraft hangar near a trailer park 4,680 feet northwest from the end of the departure runway, with the left wing hitting the ground first. 
All 258 passengers, 13 crew and 2 others on the ground were killed. This became the worst ever plane crash in the United States, not counting the September 11 attacks which were crashed by hijackers and had more ground fatalities than those passengers killed in the planes.