United Airlines Flight 409

United Airlines Flight 409 was a scheduled flight departing from Denver, Colorado to Salt Lake City, Utah. On October 6, 1955, the aircraft operating the service, a Douglas DC-4 propliner, registration crashed into Medicine Bow Peak, near Centennial, Wyoming, killing all 66 people on board (63 passengers, 3 crew members). The victims included five female members of the Mormon Tabernacle Choir and military personnel. At the time, this was the deadliest airline crash in the history of American commercial aviation. Another 66 lives had been lost earlier that year in the March 22 crash in Hawaii of a United States Navy Douglas R6D-1 Liftmaster military transport aircraft, and 66 had also died in the mid-air collision of two United States Air Force C-119G Flying Boxcars over West Germany on August 11, placing the three crashes in a three-way tie as the deadliest aviation incidents in 1955.