Today in History—April 7: That time the U.S. briefly lost a nuclear bomb

Black and white photo showing several people on a boat inspecting a recovered nuclear bomb, with orange lines highlighting the bomb's outline among parachute cords and equipment. — April 7, 1966: The U.S. military recovered a 20-megaton hydrogen bomb

At 10:33 am on this day in 1966, Spain’s embassy sent out a message and a sigh of relief: The U.S. military had finally recovered the 20-megaton hydrogen bomb it had accidentally dropped in the Mediterranean.

It was nearly 3,000 feet down, perched on a ledge. A slew of specialized equipment raised the bomb to 400 feet—where a team inside pressurized diving bells disarmed it—before bringing it to the surface.

The whole episode began as a show of force during the Cold War. The U.S. wanted to prove its military was always ready, and they did that by sending B-52 bombers armed with nukes to patrol the skies. These planes refueled mid-flight, which is exactly the challenging maneuver it sounds like.

On January 17 a bomber collided with its refueling tanker high above southeastern Spain. Seven airmen were killed. Three survivors were plucked from the sea by fishermen, and one landed safely in a field.

Four hydrogen bombs and 100 tons of debris plummeted to the earth.

The bombs’ nuclear warheads weren’t armed, but their plutonium cores were. Two exploded, raining radioactive material on the village of Palomares. A third landed intact in a riverbed, and the fourth…vanished.

A ground search turned up nothing. The break came from a fisherman who had helped rescue survivors; he’d seen something else hit the water that day. It sparked a two-month search that covered 125 square miles of seafloor.

The bomb was finally located five miles offshore. But recovering it proved just as difficult as finding it. First it fell off a cliff. Then some cables snapped. Then some cables snapped again. And again. Then the bomb moved, and they lost it again for a bit.

Fun Fact

Amazingly, no one in the village was seriously injured, “not even a chicken,” according to one reporter.

When it was finally brought ashore, the bomb was put on display for the press—the first public showing of a hydrogen bomb—just to prove that everything was finally under control.

But the consequences still linger in Palomares. Some 1,400 tons of contaminated soil were scraped up and shipped to South Carolina for storage. Areas are still cordoned off. The U.S. and Spain signed a decontamination agreement in 2015—one neither country has acted on yet.