United Air Lines Flight 629, registration N37559 and dubbed Mainliner Denver, was a Douglas DC-6B aircraft that was blown up on November 1, 1955, by a dynamite bomb placed in the checked luggage. The explosion occurred over Longmont, Colorado, United States, at 7:03 p.m. local time, while the airplane was en route from Denver to Portland, Oregon, and Seattle, Washington. All 39 passengers and 5 crew members on board were killed in the explosion and crash.

Canadian Pacific Air Lines Flight 108, known as the Sault-au-Cochon Tragedy, was a Douglas DC-3 operated by Canadian Pacific Air Lines that was blown up by a dynamite time bomb on 9 September 1949. The plane was flying from Montreal to Baie-Comeau, Quebec, with a stopover at Quebec City, when it was destroyed. All 19 passengers and 4 crew members were killed in the explosion and crash.