On February 5, 1958, a U.S. Air Force B-47 Stratojet bomber collided in mid-air with an F-86 Sabre fighter jet near Tybee Island and Savannah, Georgia. The crew requested permission to jettison the bomb, in order to reduce weight and prevent the weapon from exploding during an emergency landing. Permission was granted, and the bomb was jettisoned at 7,200 feet, while the plane was traveling at about 200 knots mph. The crew did not see an explosion when the weapon struck the sea.
The Mark 15 nuclear bomb, or Mk-15, was a 1950s American thermonuclear bomb, the first relatively lightweight (7,600 lb) thermonuclear bomb created by the US. A total of 1,200 Mark 15 bombs were produced from 1955 to 1957. There were three production variants: Mod 1, Mod 2, and Mod 3. The design was in service from 1955 to 1965.
The USAF claims it was a dummy warhead in a “Temporary Custodian Receipt”:
The search lasted ten weeks before the bomb was declared irretrievably lost, and in 2001 the Air Force concluded that leaving it in the silt was safer than digging it up, so it’s officially down there, somewhere near the beach, for good.
Was the warhead real? Who knows.
However, according to 1966 Congressional testimony by Assistant Secretary of Defense W.J. Howard, the Tybee Island bomb was a “complete weapon, a bomb with a nuclear capsule” and one of two weapons lost that contained a plutonium trigger.
The bomber was on a night training run simulating a combat mission. After the midair collision at 36,000 feet, with a wing damaged, the pilot couldn’t risk landing with the weapon aboard. He got clearance to jettison, turned over Wassaw Sound, and let it go from 7,200 feet. No explosion. Everybody lived; the pilot got the Distinguished Flying Cross. Air Force and Navy teams dragged the sound from February into April and found nothing. The bomb sank into sand and tidal mud, and the Air Force’s own estimate puts it five to fifteen feet under by now. The Air Force says the bomb was carried without its plutonium capsule and can’t go off. A 1966 statement to Congress by an assistant secretary of defense calls it “a complete weapon.” Those two things are still both on the record.
The beach at Tybee is twenty minutes from downtown Savannah. By 2007, no undue levels of unnatural radioactive contamination have been detected in the regional Upper Floridan aquifer by the Georgia Department of Natural Resources
In 2004, retired Air Force Lt. Colonel Derek Duke claimed to have narrowed the possible resting spot of the bomb down to a small area approximately the size of a football field. He and his partner located the area by trawling in their boat with a Geiger counter in tow. Secondary radioactive particles four times naturally occurring levels were detected and mapped, and the site of radiation origination triangulated. An Air Force nuclear weapons adviser speculated that the source of the radiation was natural, originating from deposits of monazite, a locally occurring mineral that emits radiation.











