Command and Control

Less than a month later, Walter Gregg and his son, Walter Junior, were in the toolshed outside their home in Mars Bluff, South Carolina, when a Mark 6 atomic bomb landed in the yard. Mrs. Gregg was inside the house, sewing, and her daughters, Helen and Frances, aged six and nine, were playing outdoors with a nine-year-old cousin. The Mark 6 had a variable yield of anywhere from 8 to 160 kilotons, depending on the type of nuclear core that was used. The bomb that landed in the yard didn’t contain a core. But the high explosives went off when the weapon hit the ground, digging a crater about fifty feet wide and thirty-five feet deep. The blast wave and flying debris knocked the doors off the Gregg house, blew out the windows, collapsed the roof, riddled the walls with holes, destroyed the new Chevrolet parked in the driveway, killed half a dozen chickens, and sent the family to the hospital with minor injuries.

The atom bomb had been dropped by a B-47 en route from Hunter Air Force Base near Savannah, Georgia, to Bruntingthorpe Air Base in Leicestershire, England. The locking pin had been removed from the bomb before takeoff, a standard operating procedure at SAC. Nuclear weapons were always unlocked from their bomb racks during takeoff and landing — in case the weapons had to be jettisoned during an emergency. But for the rest of the flight they were locked to the racks. Bombs were locked and unlocked remotely on the B-47, using a small lever in the cockpit. The lever was attached by a lanyard to the locking pin on the bomb. As the B-47 above South Carolina climbed to an altitude of about fifteen thousand feet, a light on the instrument panel said that the pin hadn’t reengaged. The lever didn’t seem to be working. The pilot told the navigator, Captain Bruce Kulka, to enter the bomb bay and insert the locking pin by hand.

Kulka couldn’t have been thrilled with the idea. The bomb bay wasn’t pressurized, the door leading to it was too small for him to enter wearing a parachute, and he didn’t know where the locking pin was located, let alone how to reinsert it. Kulka spent about ten minutes in the bomb bay, looking for the pin, without success. It must be somewhere above the bomb, he thought. The Mark 6 was a large weapon, about eleven feet long and five feet in diameter, and as Kulka tried to peek above it, he inadvertently grabbed the manual bomb release for support. The Mark 6 suddenly dropped onto the bomb bay doors, and Kulka fell on top of it. A moment later, the eight-thousand-pound bomb broke through the doors. Kulka slid off it, got hold of something in the open bomb bay, and held on tight. Amid the gust and roar of the wind, about three miles above the small farms and cotton fields of Mars Bluff, he managed to pull himself back into the plane. Neither the pilot nor the copilot realized the bomb was gone until it hit the ground and exploded.

The accident at Mars Bluff was impossible to hide from the press. Although Walter Gregg and his family had no idea what destroyed their home, the pilot of the B-47, unable to communicate with Hunter Air Force Base, told controllers at a nearby civilian airport that the plane had just lost a “device.” News of the explosion quickly spread. The state police formed checkpoints to keep people away from the Gregg property, and an Air Force decontamination team arrived to search for remnants of the Mark 6. Unlike the accident at Sidi Slimane, this one couldn’t have produced a nuclear yield — and yet it gained worldwide attention and inspired a good deal of fear. “Are We Safe from Our Own Atomic Bombs?” the New York Times asked. “Is Carolina on Your Mind?” echoed London’s Daily Mail. The Soviet Union claimed that a nuclear detonation had been prevented by “sheer luck” and that South Carolina had been contaminated by radioactive fallout.

The Strategic Air Command tried to counter the Soviet propaganda with the truth: there’d never been a risk of nuclear detonation, nor of harmful radioactivity. But SAC also misled reporters. During a segment entitled “‘Dead’ A-Bomb Hits U.S. Town,” Ed Herlihy, the narrator of a popular American newsreel, repeated the official line, telling nervous movie audiences that this was “the first accident of its kind in history.” In fact, a hydrogen bomb had been mistakenly released over Albuquerque the previous year. Knocked off balance by air turbulence while standing in the bomb bay of a B-36, the plane’s navigator had steadied himself by grabbing the nearest handle — the manual bomb release. The weapon broke through the bomb doors, and the navigator held onto the handle for dear life. The H-bomb landed in an unpopulated area, about one third of a mile from Sandia. The high explosives detonated but did not produce a nuclear yield. The weapon lacked a core.