10 Notable Accidents Involving U.S. Nuclear Weapons

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Since the introduction of nuclear weapons in 1945, the United States has sought to balance the security of its nuclear assets with the ability to deploy them if needed. The Department of Defense’s Nuclear Surety Program seeks to safeguard weapons from theft, loss, destruction or jettison. But given the thousands of warheads in service through the years — an inventory that currently stands at 2,576 warheads, down from a high of 31,000 during the Cold War — accidents happen. The most serious incidents include what is known as a Broken Arrow, a nuclear-related loss or accident that does not create the risk of war. According to the Brookings Institution, 11 nuclear bombs have been lost and remain unrecovered. The DoD has reported hundreds of nuclear weapons mishaps, many of which are lesser incidents known as Dull Swords. Here are 10 notable accidents involving nuclear weapons in U.S. history.


10. The Damascus, Arkansas Incident

An ICBM explosion in Arkansas in 1980 blew a warhead out of the launch silo.

The warhead from a Titan II missile like this one exploded through a launch hatch in Arkansas after a fuel leak in 1980.

Launch Complex 374-7 in Van Buren County, Arkansas, was the site of a nuclear accident that began on Sept. 18, 1980, when a worker dropped a wrench socket that fell 80 feet down a silo and ruptured a first-stage fuel tank on a Titan II missile. The resulting fuel leak prompted evacuation of the area, but the next day, a massive explosion blew the silo’s 740-ton cover 600 feet outside the launch complex. The W-53 nuclear warhead was ejected during the explosion and landed nearby, intact with no leakage of radioactive material. One airman was killed and 21 others were injured during the explosion and rescue efforts.


9. The Palomares Incident

Four nuclear bombs were dropped along the Spanish coast in 1966.

Recovery personnel pose with the nuclear bomb retrieved from almost 3,000 feet deep in the Mediterranean Sea.

On Jan. 17, 1966, a B-52 loaded with four nuclear weapons collided with a tanker during midair refueling operations above the coast of Spain. Both aircraft were lost, along with three of the seven crewmen aboard the B-52 and the entire four-man crew of the tanker. Three of the weapons were recovered on land near the village of Palomares, Spain; the high explosives in two of the bombs had detonated, dispersing plutonium in the area. The fourth bomb was recovered from the Mediterranean Sea after a lengthy and expensive salvage operation involving thousands of workers. Local residents were tested for the effects of radiation poisoning through the mid-1980s.


8. The Mars Bluff Incident

The U.S. Air Force accidentally dropped a nuclear bomb on Mars Bluff, S.C., in 1958.

A Mark 6 nuclear bomb similar to the one that was accidentally dropped on Mars Bluff, S.C., in 1958.

A majority of nuclear mishaps are the result of a collision or accident in the air or at sea, but the March 11, 1958 mishap near Florence, South Carolina, is unique. A bomb-rack malfunction aboard a B-47E caused the inadvertent release of an atomic bomb, which destroyed a home and injured several people on the ground in the tiny community of Mars Bluff. While the conventional explosives aboard the weapon detonated upon impact, boring a 35-foot-deep crater, the plutonium core was not triggered and remained intact. According to the Columbia (S.C.) Star, a local photographer who was one of the first on the scene of the accident talked to a Civil Air Patrol officer who allegedly overheard a radio transmission from the plane’s bombardier: “Oh, s—, I dropped the damn thing.”


7. Collision at Sea

A collision between two U.S. Navy ships in the Mediterranean in 1975 resulted in a Broken Arrow alert.

The USS Belknap had nuclear weapons aboard when a fire erupted after a collision with the USS John F. Kennedy in 1975.

One nuclear incident that has never been publicly acknowledged by the Pentagon or Navy occurred on Nov. 22, 1975 when the cruiser USS Belknap collided with the aircraft carrier USS John F. Kennedy during nighttime training exercises in the Mediterranean Sea. Both ships were heavily damaged, and fuel spread onto the Belknap, which burned for hours. According to U.S. government documents uncovered by Greenpeace, minutes after the disaster, the commander of the Sixth Fleet Carrier Strike Force issued a Broken Arrow alert involving the nuclear weapons aboard; the report was confirmed years later by a retired admiral who was on the Belknap that night.


6. The Savannah River Incident

A nuclear bomb lost off the coast of Georgia in 1958 has never been recovered.

A Mark 15 hydrogen bomb similar to that lost near Savannah, Georgia, in 1958.

On Feb. 5, 1958, a mid-air collision between a USAF F-86 fighter jet and a B-47 bomber prompted the jettison of a nuclear bomb in the waters off Tybee Island, Georgia. Although both aircrews managed to eject or land safely, the bomb has never been found. Searchers thought they had located the bomb in 2004, but to date, it remains unrecovered. There is some debate over whether the bomb remains a threat more than a half-century later. Some fear the bomb’s casing could erode in the saltwater, allowing the enriched uranium to poison a water aquifer on the coast. Others worry the bomb may have been recovered by terrorists.


5. Disappearance of the USS Scorpion

The USS Scorpion was lost at sea in 1968.

The USS Scorpion was lost at sea in 1968, with a loss of 99 crew members and two nuclear-tipped torpedoes.

The disappearance of the USS Scorpion on May 22, 1968 remains one of the great mysteries in modern military history. Lost at sea in the mid-Atlantic, it is suspected that a torpedo aboard accidentally armed and detonated in the mid-Atlantic. Classified information released by the U.S. Navy in 1993 suggests evidence that the captain had ordered the sub to make a 180-degree turn moments before disaster, perhaps in an effort to cause the inertial sensor on the torpedo to disarm. The Scorpion remains under 9,800 feet of water, complete with its nuclear reactor and two nuclear warheads. All 99 men aboard were killed.


4. The “Demon Core” Incidents

There were a couple of fatal accidents at Los Alamos National Laboratory in 1945 and 1946.

A recreation of the Demon Core incident that occurred in 1946.

Early in the U.S. nuclear weapons program, a plutonium core gained infamy as “The Demon Core” after being involved in two deadly incidents, one in 1945 and another in 1946 at Los Alamos National Laboratory in New Mexico. The first involved the accidental dropping of a tungsten carbide brick on the core; the second was a slip of a screwdriver. Both caused critical mass reactions and radiation exposure, resulting in two immediate radiation-related fatalities; three more deaths in later years were attributed to poisoning from the second incident.


3. The Thule, Greenland Incident

A fiery crash at Thule AFB in Greenland in 1968 contaminated the area.

A 2006 photo of Thule Air Base, site of a dangerous nuclear weapons accident in 1968.

On Jan. 21, 1968, a B-52 carrying four hydrogen bombs while on strategic alert crashed outside of Thule AFB in Greenland, resulting in a massive fire. Harsh Arctic weather hampered salvage operations, but more than 10,000 tons of contaminated snow, ice and bomb fragments were eventually shipped to the U.S. for disposal. The incident caused a political squabble between the U.S. and Denmark over the presence of nuclear weapons on Danish territory. In the late 1980s, almost 200 Danish workers sued the United States for damages, citing illnesses they linked to the cleanup effort, but the suit was disallowed.


2. The USS Ticonderoga Incident

A plane that fell off the USS Ticonderoga in 1965 sank in the Pacific with a nuclear weapon aboard.

The USS Ticonderoga in 1966, the year after a plane loaded with a nuclear bomb fell off the ship’s deck.

One of the more controversial accidents involving nuclear weapons occurred Dec. 5, 1965 when an A-4E Skyhawk fell off the pitching deck of the aircraft carrier USS Ticonderoga as it sailed from Vietnam on its way to Japan. The pilot perished in the incident, and its B43 nuclear bomb payload has never been recovered. Yet the U.S. government covered up the incident at the time for a couple of reasons. First, it didn’t want questions raised about why planes were carrying nuclear weapons near Vietnam. Also, the incident allegedly occurred only 80 miles from territory belonging to Japan, which for obvious reasons adamantly opposed nuclear weapons. The matter was so controversial that in 1981, when the U.S. finally admitted the mishap, Japanese officials were furious.


1. The Goldsboro, North Carolina Incident

A nuclear bomb lost in Goldsboro, North Carolina, in 1961 had all but one of the steps needed to arm it completed.

The Mark 39 nuclear bomb recovered after a 1961 crash in North Carolina.

Arguably the most frightening accident involving nuclear weapons occurred Jan. 24, 1961, when a B-52 bomber exploded in midair due to a fuel leak after departure from Seymour Johnson Air Force Base in North Carolina. Three of the crewmen aboard were killed, and two of the aircraft’s Mark 39 hydrogen bombs were released. Alarmingly, one weapon had all but one of the steps in its arming chain completed prior to impact; only the pilot’s initial activation was needed for a possible detonation. All nuclear material was recovered from the crash site except for a mass of uranium estimated to lie 55 feet below ground on a plot of land now fenced off and monitored by the U.S. Air Force.


One More: The Minot-Barksdale B-52 Incident

This incident is fresh in the minds of many. It occurred on Aug. 29, 2007 when a B-52 flew from Minot AFB, North Dakota to Barksdale AFB, Louisiana loaded with six cruise missiles, complete with nuclear warheads installed. This is not an unusual occurrence, as nuclear-loaded aircraft flew over U.S. soil on alert throughout the Cold War and continue to do so during transport of nuclear weapons. What was unique was that the chain of custody was lost for 36 hours, as no one at Minot noticed that the warheads were missing or present on the aircraft until noticed by the ground crew at Barksdale. This break in the chain of custody would be considered a Bent Spear, although the U.S. Air Force has never formally classified the event as such. The event resulted in an overhaul of procedures and disciplinary action, including the removal of the 5th Bomb Wing Commander at Minot and the resignation of the Secretary of the Air Force and the Air Force Chief of Staff.


David Dickinson retired from the United States Air Force in 2007 at the rank of E-7 Master Sergeant. He was an Aircraft Armament Systems Specialist for over 20 years, serving in the 1st Gulf War, South Korea, Somalia, and the global war on terror. He also served as an instructor for Nuclear Surety.


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David Dickinson is a backyard astronomer, science educator and retired military veteran. He lives in Hudson, Fla., with his wife, Myscha, and their dog, Maggie. He blogs about astronomy, science and science fiction at www.astroguyz.com.