Broken Arrow: A History of America’s Nuclear Weapon Accidents

Introduction

On January 24, 1961, a U.S. Air Force B-52 Stratofortress bomber carrying two powerful hydrogen bombs suffered a catastrophic failure high above North Carolina. The massive aircraft broke apart in mid-air, sending its crew and its nuclear payload plummeting towards the ground near the town of Goldsboro. One of the bombs plunged into a muddy field at over 700 miles per hour, its tail found buried 20 feet deep. The other bomb’s parachute deployed, a sign that its automatic arming sequence had begun. It drifted down and snagged in a tree, its warhead largely intact. Later analysis would reveal a terrifying truth: of the multiple safety mechanisms designed to prevent an accidental detonation, all but one had failed. A single, low-voltage switch was all that prevented a nuclear explosion that would have dwarfed the Hiroshima blast.

This harrowing event was not an isolated incident. It was an example of what the U.S. military officially calls a “Broken Arrow”—an accident involving a nuclear weapon. Between 1950 and 1980, the Pentagon officially acknowledged 32 such accidents. This history is not just a collection of close calls; it’s a story of how the strategic doctrines of the Cold War made these events almost inevitable, a chronicle of human and mechanical failures in a system of unimaginable power, and a testament to the hard-won safety lessons that emerged from the wreckage.

Defining a Nuclear Mishap

The U.S. Department of Defense uses the term “Broken Arrow” to classify an unexpected event involving nuclear weapons or their components that results in accidental launching, firing, detonation, theft, or loss, but does not create a risk of nuclear war. This can range from a weapon being consumed by fire to radioactive contamination to a weapon being jettisoned or lost in transit.

The term is part of a specific lexicon the military developed to categorize nuclear incidents by severity, allowing for a calibrated response. This system reveals an institutional effort to manage a spectrum of previously unimaginable risks. The careful distinction between a minor deficiency and a potential trigger for war shows a bureaucracy grappling with the immense responsibility of its arsenal. The main classifications include:

• NUCFLASH: The most serious category, referring to an incident involving the possible detonation of a nuclear weapon that creates a risk of war. This could be an accidental or unauthorized launch of a nuclear-armed missile toward another nuclear-capable country.
• BENT SPEAR: A significant incident involving a nuclear weapon or its components that requires major rework or could cause adverse public reaction, but isn’t severe enough to be a Broken Arrow. A notable example occurred in 2007, when a B-52 bomber was mistakenly armed with six nuclear-tipped cruise missiles and flown across the country undetected for hours.
• EMPTY QUIVER: The specific code word for the seizure, theft, or loss of a U.S. nuclear weapon.
• DULL SWORD: The most common type of report, used to identify a nuclear safety deficiency or a minor incident, such as an issue with equipment or procedures.
• FADED GIANT: An accident involving a military nuclear reactor, such as those on submarines or aircraft carriers, rather than a nuclear weapon itself.

While the Pentagon’s official list contains 32 Broken Arrow incidents, declassified documents from the Defense Atomic Support Agency show that hundreds of other, less severe events—likely classified as Bent Spears or Dull Swords—also occurred. This highlights that the official public narrative was often a carefully managed version of a much messier reality. The distinction was a key tool for preventing public alarm during the tense decades of the Cold War.

U.S. Military Nuclear Incident Terminology

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The Cold War Imperative

The frequency of nuclear accidents during the Cold War wasn’t just a matter of bad luck; it was a direct consequence of U.S. strategic policy. To deter the Soviet Union, the United States relied on a nuclear triad: land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and a fleet of strategic bombers. The goal was to ensure that enough of the arsenal could survive a surprise attack to launch a devastating retaliatory strike, a doctrine known as Mutually Assured Destruction (MAD).

To make this deterrent credible, the Strategic Air Command (SAC) implemented airborne alert programs, the most famous being “Operation Chrome Dome.” This policy kept a portion of the B-52 bomber fleet, armed with thermonuclear weapons, in the air 24 hours a day, 365 days a year. These constant flights, involving grueling hours and risky mid-air refuelings, dramatically increased the statistical probability of a mishap.

The risk wasn’t confined to strategic bombers. The U.S. also deployed thousands of smaller, tactical nuclear weapons across Europe and other allied territories. These were intended for use on a “limited” nuclear battlefield to offset the Soviet Union’s conventional military superiority. Specialized units like the Army’s “Green Light teams” were even trained to carry portable nuclear weapons, known as Atomic Demolition Munitions (ADMs), behind enemy lines to destroy key infrastructure.

This created a profound paradox. The very actions taken to make the nuclear deterrent credible—and thus prevent a war—created a massive, complex, and constantly stressed system that was ripe for failure. The history of Broken Arrows is the story of this paradox playing out, where the effort to prevent the ultimate catastrophe made smaller, yet still potentially devastating, accidents far more likely.

A Decade of Close Calls: The 1950s

The first decade of the nuclear age was marked by a series of accidents that revealed the inherent dangers of handling and transporting these new weapons. Many early incidents involved aircraft crashes where, fortunately, a full nuclear detonation was impossible because the weapon’s fissile core—its plutonium “pit”—was transported separately from the main bomb assembly as a key safety measure. Even so, the conventional high explosives in the bombs often detonated, causing significant destruction.

Case Study: The Kirtland Air Force Base Incident (1957)

On May 22, 1957, a B-36 bomber was ferrying a 42,000-pound Mark 17 hydrogen bomb—one of the largest ever made by the U.S.—to Kirtland Air Force Base in New Mexico. As the plane prepared for landing, it hit a patch of turbulence. A crewman in the bomb bay lost his balance and, to steady himself, grabbed the only thing available: the emergency bomb release handle. The massive weapon tore through the closed bomb bay doors and fell 1,700 feet. Its conventional explosives detonated on impact, blasting a crater 12 feet deep and 25 feet wide. The only reported casualty was a nearby cow. A nuclear catastrophe was averted only because the plutonium core was being stored in a separate part of the aircraft.

Case Study: The Mars Bluff Incident (1958)

Less than a year later, on March 11, 1958, a B-47 bomber heading overseas from Georgia accidentally jettisoned a nuclear weapon over rural Mars Bluff, South Carolina. The bomb’s high-explosive trigger detonated when it hit the ground in a family’s garden. The blast destroyed their home, injured six family members, and left a crater 70 feet wide and 30 feet deep. As with the Kirtland incident, a nuclear yield was prevented because the bomb’s fissile core had not yet been installed.

These early events were not caused by enemy action or complex sabotage, but by mundane, relatable failures: engine trouble, a faulty mounting shackle, or, in the case of Kirtland, a man simply trying to keep his balance. They demonstrated that human fallibility was a critical variable in a system of immense technological power. Even with safety protocols like separate core storage, the simple act of moving these weapons created constant opportunities for error.

On the Brink of Disaster: The 1960s

As the Cold War intensified, so did the risks. Airborne alert missions became routine, and weapons became more sophisticated, with their nuclear cores often permanently installed. The 1960s saw some of the most dangerous Broken Arrow accidents, pushing the United States to the very edge of an accidental nuclear detonation on its own soil and abroad.

Case Study: The Goldsboro B-52 Crash (1961)

The mid-air disintegration of a B-52 over Goldsboro, North Carolina, remains one of the most chilling nuclear close calls in history. As detailed earlier, the incident involved two Mark 39 hydrogen bombs, each with a yield of up to 4 megatons. The fact that one bomb went through nearly its entire arming sequence before a single switch halted the process was a stark wake-up call. It revealed that the complex web of safety mechanisms designed in a lab could fail sequentially in the chaos of a real-world accident.

Case Study: The Palomares B-52 Crash (1966)

On January 17, 1966, a B-52 bomber and a KC-135 refueling tanker collided high over the Mediterranean coast of Spain. Both planes were destroyed. The B-52’s payload of four 1.5-megaton hydrogen bombs was scattered. Three of the bombs fell on or near the small fishing village of Palomares. The conventional high explosives in two of these bombs detonated on impact, creating clouds of highly radioactive plutonium dust that contaminated over 650 acres of farmland. The third bomb that fell on land was recovered relatively intact.

The fourth bomb fell into the Mediterranean Sea, triggering an unprecedented 80-day search and recovery operation. The U.S. Navy deployed nearly 12,000 personnel and a fleet of ships and submersibles to find the missing weapon. The incident forced the U.S. to publicly acknowledge the accident. To prove the water was safe, the U.S. ambassador to Spain famously went for a swim for reporters. Eventually, the bomb was located and recovered from a depth of nearly 2,900 feet. The cleanup on land was a massive undertaking, requiring over 1,400 tons of contaminated soil to be scraped up and shipped to a nuclear waste facility in South Carolina.

Case Study: The Thule Air Base B-52 Crash (1968)

Just two years later, on January 21, 1968, another B-52 accident caused widespread radioactive contamination, this time in the fragile Arctic environment. A bomber flying a top-secret “Hard Head” mission to monitor the Ballistic Missile Early Warning System (BMEWS) radar at Thule Air Base, Greenland, experienced an uncontrollable cabin fire. The crew ejected, and the pilotless aircraft crashed onto the sea ice of North Star Bay, about seven miles from the base.

The impact and subsequent fire caused the conventional explosives in all four of its hydrogen bombs to detonate. The blasts shattered the weapons and scattered plutonium, uranium, and other radioactive debris over a wide area. The ensuing cleanup, codenamed “Project Crested Ice,” was a monumental effort conducted in perpetual darkness and extreme cold, with temperatures dropping below -70°F. Working in hazardous conditions, a team of U.S. personnel and local Greenlandic Inuit workers removed some 237,000 cubic feet of contaminated ice, snow, and wreckage, which was sealed in containers and shipped to the United States for disposal.

The End of an Era: The Damascus Titan Missile Explosion (1980)

The last of the 32 officially acknowledged Broken Arrow incidents occurred not in the air, but deep within a missile silo. On September 18, 1980, a maintenance crew was performing a routine procedure on a Titan II ICBM near Damascus, Arkansas. An airman accidentally dropped a heavy wrench socket, which fell 70 feet, bounced off a platform, and punctured the missile’s pressurized fuel tank.

For over eight hours, military officials grappled with the leak of highly volatile rocket fuel. Their efforts failed. The silo exploded in a massive fireball that killed one airman, injured 21 others, and launched the missile’s 740-pound reentry vehicle—containing a 9-megaton W53 warhead, the most powerful in the U.S. arsenal—out of the silo. The warhead landed in a ditch a few hundred feet away. Its safety features held. This event, caused by a single, simple mistake, highlighted the dangers of the aging liquid-fueled ICBM fleet and marked a symbolic end to the most accident-prone period of the nuclear age.

The Legacy of Broken Arrows

The decades of close calls and near-catastrophes, while terrifying, were not without a positive outcome. They forced a profound and necessary revolution in nuclear weapon safety design and handling protocols. The chronology of accidents and subsequent safety innovations reveals a clear pattern: the U.S. nuclear arsenal became safer not because designers anticipated every failure, but because real-world accidents exposed horrifying vulnerabilities. Each Broken Arrow served as an unscheduled, high-stakes safety test, with the lessons written in the debris of crashed bombers and contaminated landscapes.

A Revolution in Safety

The near-disasters at Goldsboro, Palomares, and Thule were particularly influential, spurring the development of multiple layers of safety technology.

• Permissive Action Links (PALs): These are coded locks integrated into a weapon’s arming system. A weapon with a PAL cannot be detonated without the insertion of the correct code, preventing unauthorized use or the kind of sequential arming seen at Goldsboro.
• Environmental Sensing Devices (ESDs): These are sensors that prevent a weapon from arming until they detect the specific conditions of its intended use, such as the G-forces of a missile launch or the characteristics of free-fall from a bomber.
• One-Point Safe Design: Weapons were re-engineered to be “one-point safe,” ensuring that the detonation of the conventional high explosives at a single point—from a fire, impact, or even a bullet—could not trigger a nuclear yield.
• Insensitive High Explosives (IHE): The plutonium dispersal at Palomares and Thule was caused by the detonation of conventional explosives. This led to the development of IHE, which are far more stable and extremely unlikely to detonate when subjected to fire, shock, or impact.
• The Walske Criteria: After the Palomares accident, the Department of Defense established strict, quantitative safety standards. These criteria required that the probability of an accidental nuclear detonation must be less than one in a million during an abnormal event (like a crash or fire) and less than one in a billion during normal operations.

Declassification and Public Awareness

For decades, the details of these incidents were shrouded in secrecy under the official policy to “neither confirm nor deny” the presence of nuclear weapons at any specific location. Information began to slowly emerge in the 1980s and 1990s as documents were declassified through the Freedom of Information Act.

This led to significant political fallout. The revelations about the 1968 Thule crash created a major scandal in Denmark in the 1990s, dubbed “Thulegate.” Declassified documents proved that the U.S. had not only flown nuclear-armed bombers over Greenland routinely but had also stored nuclear weapons on the ground there, directly violating Denmark’s non-nuclear policy and contradicting years of official denials from both governments. This history illustrates a fundamental tension between the perceived needs of national security and the principles of democratic accountability.

Modern Response Protocols

The lessons from these historical accidents are now codified in the military’s Nuclear Weapon Accident Response Procedures (NARP) manual. This is a comprehensive, multi-agency plan that establishes a clear command structure and detailed procedures for responding to any nuclear weapon accident. It involves close coordination between the Department of Defense, the Department of Energy, the FBI, and other federal and local agencies. Under current protocols, every nuclear weapon accident is immediately treated as a potential hostile act until an investigation by the FBI proves otherwise.

Lost and Never Found

While cleanup operations like Project Crested Ice were monumental efforts to contain damage, some accidents left a permanent and unresolved legacy. During the Cold War, the U.S. military lost six nuclear weapons that were never recovered. These incidents serve as a stark, physical reminder that not all consequences of the nuclear age could be managed or mitigated.

The lost weapons include:

• A Mark 4 bomb jettisoned from a B-36 bomber off the coast of British Columbia in 1950.
• Two nuclear weapon cores lost when a B-47 bomber disappeared over the Mediterranean Sea in 1956.
• A Mark 15 hydrogen bomb jettisoned into Wassaw Sound near Savannah, Georgia, after a mid-air collision in 1958.
• One of the two Mark 39 hydrogen bombs from the 1961 Goldsboro crash, which was never fully excavated from the swampy ground.
• A B43 hydrogen bomb lost when an A-4E Skyhawk attack jet rolled off the aircraft carrier USS Ticonderoga into the Philippine Sea in 1965.
• Two nuclear-tipped torpedoes that went down with the submarine USS Scorpion when it sank in the Atlantic in 1968.

Broken Arrow in Popular Culture

The term “Broken Arrow” has entered the public lexicon, but often in a way that misrepresents its official meaning.

• The 1996 action film Broken Arrow, starring John Travolta and Christian Slater, famously depicts the theft of two nuclear bombs by a rogue Air Force pilot. While the film brought the term to a wide audience, its plot actually describes what the military would classify as an “Empty Quiver” (theft of a weapon), not a “Broken Arrow” (an accident).
• The 2002 film We Were Soldiers uses the term for its other, non-nuclear military definition: a battlefield distress call from a ground unit about to be overrun, requesting immediate air support from all available aircraft. This has added another layer of public confusion about the term’s specific nuclear context.

Summary

A “Broken Arrow” is a U.S. military term for an accident involving a nuclear weapon that does not create a risk of war. It is one part of a detailed classification system designed to manage the unique risks of the nuclear arsenal. The 32 officially acknowledged incidents between 1950 and 1980 were a direct result of the high-stakes strategic posture of the Cold War, particularly the constant airborne alert missions that subjected nuclear-armed aircraft to thousands of hours of flight and risky operations.

Near-catastrophes like the crashes at Goldsboro, Palomares, and Thule exposed critical vulnerabilities in weapon design and handling procedures. These terrifying events forced a reactive but ultimately successful revolution in nuclear weapon safety, leading to multiple layers of redundant safety features that make today’s arsenal far more secure. The history of Broken Arrows is a sobering chronicle of how close the world came to nuclear disaster by accident, and a powerful lesson in the immense challenge of managing humanity’s most dangerous creations.

Appendix: Officially Acknowledged Broken Arrow Incidents (1950-1980)

The U.S. Department of Defense has publicly acknowledged 32 “Broken Arrow” accidents that occurred between 1950 and 1980.