Northwest Orient Airlines Flight 2501 was a DC-4 propliner operating its daily transcontinental service between New York City and Seattle when it disappeared on the night of June 23, 1950. The flight was carrying 55 passengers and three crew members; the loss of all 58 on board made it the deadliest commercial airliner accident in American history at the time.

• http://en.wikipedia.org/wiki/Northwest Orient Airlines Flight 2501