Date: June 30, 1956
Location: Grand Canyon, Arizona
Aircraft: Douglas DC-7 / Lockheed S Constellation
Reg: N6902C/N6324C
Airline: United Air Lines
Flight No: 718 / 1
Fatalities: 128 : 128

The wreckage of a United Airlines DC-7 after it collided with a TWA Constellation over the Grand Canyon in Arizona.  All 128 people on both planes were killed.