U.S. Nuclear Weapons Destroyed Over Canada Two Bombs Were Dumped In Separate 1950 Incidents

American bomber crews twice have destroyed nuclear weapons over Canadian territory, according to a new study by a Canadian military historian.

The bombs were dumped and detonated in separate incidents in 1950 after U.S. aircraft became disabled, one off British Columbia, the other over Quebec.

Nuclear material had been removed from the bombs’ cores so the blasts were not nuclear explosions, relying instead on the powerful chemical explosives used in atomic bombs, author John Clearwater said in an interview from Ottawa.

The force of the explosions was therefore a tiny fraction of the bombs dropped on Japan during the Second World War, but they did release nearly 100 pounds of uranium into the air, he said.

The first incident occurred Feb. 13, 1950, when a B-36 bomber lost three of its six engines en route from Fairbanks, Alaska, to Fort Worth, Texas.

Following standard procedure for such emergencies, the crew released its nuclear bomb and detonated it about 3,600 feet over the Pacific Ocean off Vancouver Island. The 17 people on board then bailed out before the aircraft crashed into a mountain. Five people died.

The atomic bomb, either a Mark III or Mark IV, used a conventional high explosive to trigger nuclear fission but the plutonium core had been removed for safety. However, a casing of uranium - designed to boost the force of the nuclear explosion - remained.

The second, more serious incident occurred Nov. 10, 1950.

A four-engine American B-50 bomber carrying a Mark IV bomb from a military exercise in Goose Bay, Newfoundland, to its home base in Tucson, Ariz., ran into engine trouble over the St. Lawrence River.

The bomb, also lacking its essential plutonium core, was detonated near Riviere-du-Loup, Quebec, at 2,500 feet. “I have the confirmation from the crew on board,” Clearwater said.

The blast shook the ground and terrified residents.

The U.S. Air Force covered up the incident by saying a load of 500-pound conventional practice bombs had been jettisoned near the town. The B-50 landed safely.

The Mark III bomb was the same weapon that devastated Nagasaki. The Mark IV was an improved version.