SAC (sort of) Nukes Kids' Playhouse
On the afternoon of March 11, 1958, the Gregg sisters—Helen, six, and Frances, nine—and their cousin Ella Davies, nine, were in the playhouse their father had built for them in the woods behind their house in Mars Bluff, South Carolina. About four o’clock they tired of the playhouse and moved 200 feet to the side yard. This kept them from becoming the first Americans killed by a nuclear weapon released on U.S. territory. U.S. Air Force B-47E medium bomber serial number 53-1876A dropped its nuclear weapon in the woods behind the Greggs’ house at 4:19 P.M. The high-explosive trigger in the bomb blew up on contact with the ground, leaving a crater 50 feet across and 35 feet deep and injuring the three girls. All that remained of the playhouse were a few twisted shards of the corrugated metal that had been its roof.
OK, you're probably thinking "Geez, first they accidentally drop a nuke, and then score a bulls eye on the kids' playhouse. What are the odds of that???" But really, it gets even better. How do you think they dropped it in the first place???
Right Out Of Dr. Strangelove
At 3:51, as required by regulations, co-pilot Woodruff rotated his seat to face aft and pulled the lever to disengage the locking pin from the nuclear weapon. It could now be dropped instantly in case of an emergency. At 3:53 the plane took off to join three other B-47s for a formation flight to Europe. When the B-47 reached an altitude of 5,000 feet, Woodruff again rotated his seat, this time to re-engage the locking pin. He worked the locking lever unsuccessfully for five minutes as the B-47 climbed to 15,000 feet to join the three other aircraft. At this point, the crew knew it had a problem. The pilot told the bombardier, Captain Kulka, to go into the bomb bay to try to seat the locking pin by hand. This was not a trivial decision; the bomb bay was not pressurized, so the entire plane had to be depressurized. Because the plane was at 15,000 feet, the crew had to go on oxygen. Further complicating matters, the entrance to the bomb bay was so narrow that a parachute could not be worn into it. The task was doomed from the start; later testimony indicated Kulka had no idea where to find the locking pin in the large and complicated bomb-release mechanism. After a tense 12 minutes searching for the pin, the bombardier decided, correctly, that it must be high up in the bomb bay and invisible because of the curvature of the bomb. A short man, he jumped to pull himself up to get a look at where he thought the locking pin should be. Unfortunately, he evidently chose the emergency bomb-release mechanism for his handhold. The weapon dropped from its shackle and rested momentarily on the closed bomb-bay doors with Captain Kulka splayed across it in the manner of Slim Pickens in Dr. Strangelove. Kulka grabbed at a bag that had providentially been stored in the bomb bay, while the more-than-three-ton bomb broke open the bomb-bay doors and fell earthward. The bag Kulka was holding came loose, and he found himself sliding after the bomb without his parachute. He managed to grab something—he wasn’t sure what—and haul himself to safety. Moments later the plane was rocked by the shock wave of the blast when the bomb hit the ground. An "Unscheduled" Bomb Drop
In case of an unscheduled bomb drop, Air Force regulations required the crew to immediately notify its base by a special coded message. Because the procedure had never been used, the operations center at Hunter Air Force Base did not recognize the strange incoming message. As a final indignity, the pilot was reduced to radioing an open, uncoded message to the civilian tower at the Florence airport six miles west of Mars Bluff asking them to advise Hunter by telephone that aircraft 53-1876A had lost a “device.”
Here's The Best Part
General LeMay, who was by then vice chief of staff of the Air Force, called Captain Koehler directly to get a telephone briefing on what had happened. LeMay, perhaps the only operational commander in the Air Force who had actually performed maintenance on his bombers, understood Koehler’s explanation, and the crew was released.
If we read between the lines of that last sentence we understand that the problem with the "locking pin" was probably NOT an isolated instance. We can also see that the bomb bay episode got past the censors and over to a Hollywood screenwriter who conjured up that now famous scene in Dr. Strangelove (1964) in which Slim Pickens jumps on the thermonuclear bomb, releases what must have been the jammed locking pin, and rides it all the way down. Fortunately for Captain Kulka, it didn't quite play out the same way in real life.
As for the members of the Gregg family, who lost their country dream home, the kids' playhouse and
...6 to 14 chickens (the chickens were free-range, and some were vaporized in the explosion; the Air Force was reluctant to commit itself to a spécific number without a body count)they ended up (after a protracted lawsuit against the government) moving into a "neat brick bungalow" in the city.
Learning From One's Mistakes
The Mars Bluff incident obliged the Air Force to make significant changes. The composition of the high explosive used in nuclear-weapon triggers was promptly reformulated. No longer would it be possible for the explosive trigger in a nuclear weapon to be set off by concussion; the new design required a specific electrical impulse. While the Air Force and the Department of Energy do not discuss such matters, it seems likely that the changes cost hundreds of millions of 1958 dollars. Also, within days of the accident, a regulation was published requiring that locking pins be inserted in nuclear-weapon bomb shackles at all times, including takeoffs and landings.
Fortunately, in this particular accident the "fissionable nuclear core" was NOT in the bomb at the time of the accident. Otherwise, that crater in the Gregg's back yard would have been a whole lot bigger, AND it would have been a whole lot more than "chickens" that were "vaporized."
Editor's Note: All items in italics or quotes are from the original article, “Aircraft 53-1876A Has Lost A Device”: How the U.S. Air Force came to drop an A-bomb on South Carolina, by Clark Rumrill, in American Heritage, 2000, Volume 51, Issue 5, http://www.americanheritage.com/content/%E2%80%9Caircraft-53-1876a-has-lost-device%E2%80%9D?page=show