U.S. lost, and never found, a nuclear weapon in 1968

Published 12 November 2008

A U.S. Air Force bomber carrying four nuclear bombs crashed in Greenland in 1968; three of the weapons were recovered; the fourth is still under the ice

The U.S. Air force lost, and then abandoned, a nuclear weapon beneath the ice in northern Greenland following a crash in 1968, a BBC investigation has found. The Thule Air Base, located in northwest Greenland was built in 1950 and offered the United States a valuable vantage point. Because of that, U.S. policymakers believed the Soviet Union would take out the base as a prelude to a nuclear strike against the United States.

In response, the U.S. Air Force, in 1960, began flying Chrome Dome missions. Nuclear-armed B52 bombers continuously circled over Thule, and could head straight to Moscow if they witnessed its destruction. On 21 January 1968 one of those missions went wrong. One of the Chrome Dome planes crashed on the ice, and the four nuclear bombs it carried rolled onto the ice sheet. The nuclear core of each bomb is surrounded by high explosives, and these explosives detonated, but without initiating a nuclear explosion.

The Pentagon argued that all four weapons had been “destroyed.” This may be technically true, since the bombs were no longer complete, but declassified documents obtained by the BBC under the U.S. Freedom of Information Act, reveal that only three of the weapons could be accounted for.

The underwater search was hobbled by technical problems and, as winter encroached and the ice began to freeze over, a decision was made to stop the search for the fourth weapon. Diagrams and notes included in the declassified documents make clear it was not possible to search the entire area where debris from the crash had spread.

The BBC tracked down William Chambers, a former nuclear weapons designer at the Los Alamos nuclear laboratory who once ran a team dealing with accidents, including the Thule crash. “There was disappointment in what you might call a failure to return all of the components,” he told the BBC, explaining the logic behind the decision to abandon the search. “It would be very difficult for anyone else to recover classified pieces if we couldn’t find them.”