Although the U.S. government “does not believe the bomb contains active nuclear material,” schwit1 shares this report from the BBC:
A commercial diver may have discovered a lost decommissioned U.S. nuclear bomb off the coast of Canada. Sean Smyrichinsky was diving for sea cucumbers near British Columbia when he discovered a large metal device that looked a bit like a flying saucer. The Canadian Department of National Defence believes it could be a “lost nuke” from a US B-36 bomber that crashed in the area in 1950…. The plane was on a secret mission to simulate a nuclear strike and had a real Mark IV nuclear bomb on board to see if it could carry the payload required…

The American military says the bomb was filled with lead, uranium and TNT but no plutonium, so it wasn’t capable of a nuclear explosion… Several hours into its flight, its engines caught fire and the crew had to parachute to safety… The crew put the plane on autopilot and set it to crash in the middle of the ocean, but three years later, its wreckage was found hundreds of kilometers inland.
The crew says they dumped their bomb-like cargo into the ocean first to avoid a detonation on land.

Read more of this story at Slashdot.

Source: Slashdot – Uranium-Filled ‘Lost Nuke’ Missing Since 1950 May Have Been Found