What began as a routine U.S. Air Force training mission off the coast of Georgia in the mid-1950s became one of the enduring mysteries of the Cold War. During a simulated combat exercise, a B-47 Stratojet collided midair with an F-86 Sabre. Fearing that an emergency landing with a nuclear payload could result in catastrophe, the bomber crew made the decision to jettison a Mark 15 thermonuclear weapon into the waters near Tybee Island. The device sank into Wassaw Sound and has never been recovered.
At the time, officials sought to reassure the public by stating that the bomb’s plutonium core had been removed before the flight, suggesting it posed no nuclear danger. However, later declassified documents and independent investigations have cast doubt on that claim. Some analyses suggest the weapon may still contain nuclear material, raising concerns that it remains buried beneath shifting layers of sediment offshore.
Multiple search efforts have failed to locate the device, and experts continue to debate whether recovery would be safe or even feasible. Changing seabeds, coastal erosion, and powerful storms further complicate any attempt to find it. Today, the so-called “Tybee Bomb” remains a chilling Cold War relic—symbolizing how even routine training missions carried the risk of near-catastrophic consequences.
Mid-air collision over Tybee Island
On February 5, 1958, while performing a simulated combat mission exercise, a Boeing B-47 Stratojet was involved in a mid-air collision with a North American F-86 Sabre. The B-47, having taken off from Homestead Air Force Base, Florida, was carrying a two-man crew, as well as a 7,600-pound Mark 15 nuclear bomb.
The F-86’s pilot, Lt. Clarence Stewart, hadn’t seen the B-47 on his radar and descended directly on top of it. The crash between the two caused the left wing of the fighter jet to completely rip off, while the bomber’s fuel tanks suffered heavy damage. Stewart was able to eject before his aircraft crashed, while the pilot of the B-47, Lt. Col. Howard Richardson, sought the closest landing base. Despite the damages to the bomber, the B-47 remained airborne. After dropping 18,000 feet, Richardson regained control.
As for the nuclear bomb onboard the aircraft, he granted the crew’s request to jettison it, to prevent it from exploding during the emergency landing. The bomb was dropped from 7,200 feet, over the shores of Tybee Island. The pilot and crew reported no explosion upon it meeting the water, and they were able to successfully land the damaged B-47 at Hunter Army Airfield, Georgia.
For his actions, Richardson was awarded the Distinguished Flying Cross.
A search force was sent to find the bomb
Following the 1958 Tybee Island mid-air collision, the United States Air Force initiated a major search operation to recover the missing Mark 15 thermonuclear bomb. The effort was led by the Air Force’s 2700th Explosive Ordnance Disposal Squadron and supported by approximately 100 personnel from the United States Navy, all working to eliminate the potential risk posed by the lost weapon.
For nearly ten weeks, teams searched the waters and muddy seabed of Wassaw Sound near Tybee Island. Using early sonar equipment and dragging cables across the ocean floor, they conducted a slow and systematic sweep of the area. Despite employing the best available technology of the time, no trace of the bomb was found. On April 16, 1958, officials formally ended the operation, concluding that recovery efforts were not practical.
Decades later, interest in the case resurfaced. A 2001 hydrographic study by the United States Department of Energy suggested the bomb could still be buried under five to fifteen feet of sediment, potentially intact. These findings renewed debate among experts about whether recovery efforts would pose greater danger than leaving the device undisturbed, allowing the ocean to continue concealing one of the Cold War’s most unsettling lost weapons.
Was the Mark 15 nuclear?
Since it went missing, experts have argued over whether the bomb off Tybee Island was actually nuclear. If it had a plutonium core, it would have been a complete nuclear weapon. If not, it likely had a dummy core—meaning it couldn’t trigger a nuclear blast but could still cause a powerful conventional explosion.
The Air Force claimed the bomb’s nuclear capsule had been removed before the flight and replaced with a 150-pound lead dummy. Internal documents from Strategic Air Command backed this up, stating that test flights in February 1958 weren’t cleared to carry nuclear-armed bombs.
That explanation stood for decades—until 1994. A newly declassified document included a 1966 Congressional testimony from W.J. Howard, then Assistant Secretary of Defense. In it, Howard directly contradicted the Air Force’s public stance. He told the Joint Committee on Atomic Energy that the Tybee bomb was, in fact, “a complete, fully functional bomb with a nuclear capsule” that included a plutonium trigger.
If Howard’s testimony is true, the bomb could still be extremely dangerous. A detonation would create a fireball over a mile wide and thermal radiation that could be felt up to 10 miles away.
Yet another search is launched
In 2004, armed with fresh information, Air Force veteran Lt. Col. Derek Duke privately conducted a new search for the long-lost nuclear bomb off Tybee Island. With a small team, he methodically combed the waters of Wassaw Sound, using a Geiger counter to detect any unusual radiation levels.
Their survey revealed that radiation readings near the island’s peak were about four times higher than normal—a potential sign that the Mark 15, if still armed, might be nearby. By tracing these elevated levels, the team was able to outline a target area roughly the size of a football field.
However, an Air Force review of the findings determined the radiation spike was likely due to natural causes, specifically monazite-rich sand deposits. As a result, the bomb’s precise location remains a mystery to this day.
Best to leave the nuclear bomb alone
The Air Force is content with leaving the bomb’s location a mystery, and officials have assured residents in the surrounding area that it poses no threat, so long as it’s left alone. An “intact explosive would pose a serious explosion hazard to personnel and the environment if disturbed by a recovery attempt,” they stated.
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The next time you go diving near Tybee Island, keep an eye out for the 12-foot long, 7,600-pound Mark 15 nuclear bomb with the serial number 47782. If you spot it, leave the sleeping beast alone!