December 20, 1972 (Wednesday)
- Neil Simon's play The Sunshine Boys, was first performed, at the Broadhurst Theatre on Broadway.
- The Northrop M2-F3, the "wingless airplane", made its final flight, achieving an altitude of 71,500 feet.
- The last Australian servicemen to have served in the Vietnam War were brought home.
- North Central Airlines Flight 575 was cleared for takeoff by an air traffic controller at Chicago's O'Hare Airport, but Delta Air Lines Flight 954 had not yet cleared the runway. Eleven of the 41 people on board the North Central DC-9 were killed in the collision.
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