Fred Iklé had predicted that as the number of nuclear weapons and airborne alerts increased, so would the number of accidents. He was correct, and the aircraft involved in those accidents had few safeguards to protect weapons during a crash. The Air Force considered the performance of a bomber or a fighter — its speed, maneuverability, capacity, and range — more important than its structural integrity. The B-52 had been designed in the late 1940s, and its designers never anticipated that the bomber would be used for airborne or ground alerts. It wasn’t built to carry fully assembled nuclear weapons during peacetime. When the weapons were attached to the underside of a plane, they were fully exposed to the effects of a crash. And when they were carried inside the bomb bay of a B-52, a Sandia report noted, they were located in “a weak point in the aircraft’s structure, a point at which the aircraft is apt to break open, spewing weapons beyond the protection afforded by the fuselage.”
On Johnston Island in the central Pacific, tests designed to measure the effects of high-altitude nuclear explosions served as a reminder that missiles and warheads didn’t always behave in predictable ways. On June 3, 1962, a Thor intermediate-range missile with a 400-kiloton warhead lifted off smoothly. But a radar tracking station failed, endangering ships in the area if the missile flew off course. The range safety officer decided to abort the flight. The command destruct mechanism blew up the missile, destroying its warhead. Two and a half weeks later, another Thor was launched, this time with a 1.4-megaton warhead. The missile’s engine shut down after fifty-nine seconds, and the range safety officer decided, once again, to use the command destruct mechanism. The Thor exploded at an altitude of about thirty thousand feet. Pieces of the missile and the warhead, including plutonium from its core, fell on Johnston Island and the surrounding lagoon.
About a month later, another Thor missile with a 1.4-megaton warhead misfired on the launchpad. It never got off the ground. The range safety officer gave the command destruct order, and a massive explosion destroyed much of the launch complex, showering it with debris, burning fuel, and plutonium. The next two months were spent rebuilding the complex and decontaminating the island. On October 15, during the first use of the new launchpad, a Thor missile went off course about ninety seconds after liftoff. The command destruct order was given, the missile exploded, and more plutonium fell onto Johnston Island. Two thirds of the Thor missiles used in the tests — modified versions of the Thors deployed in Great Britain — had to be destroyed by remote control.
The mishaps on Johnston Island occurred during test launches carefully planned for months. But mundane, everyday tasks also caused nuclear weapon accidents. On November 13, 1963, three workers at an Atomic Energy Commission base in Medina, Texas, were moving partially assembled Mark 7 bombs into a storage igloo. The weapons were being decommissioned. Their high explosives would eventually be burned, their uranium recovered. Two explosive spheres most likely rubbed together while being unloaded, and one of them ignited. The three workers — Marvin J. Ehlinger, Hilary F. Huser, and Floyd T. Lutz — noticed the flames, ran out of the igloo, and jumped into a ditch across the road. The sphere burned for about forty-five seconds and then detonated, setting off approximately 123,000 pounds of high explosives in the building. The explosion did not produce a nuclear yield, although the mushroom cloud rising from the blast contained uranium dust. Shop windows were blown out in San Antonio, fourteen miles away. All that remained, where the igloo had once stood, was a crater twenty feet deep. The other igloos at the base were undamaged, the three workers unharmed. They were given the rest of the day off.
A few weeks later a B-52 encountered severe air turbulence while crossing the Appalachian Mountains. It was transporting two Mark 53 hydrogen bombs — an air-delivered version of the weapon carried by the Titan II missile, with a yield of 9 megatons. The pilot, Major Thomas McCormick, took the plane down to about twenty-nine thousand feet, looking for a smoother ride. But the turbulence got worse, and McCormick received permission to climb another few thousand feet. The crew heard a loud thud. The fifty-foot-high tail fin had snapped off the bomber. McCormick told everyone to bail out, as the plane rolled over and flew upside down for a moment before spiraling downward. Four crew members got out safely; the radar navigator, Major Robert Townley, didn’t. The plane crashed into the side of Savage Mountain, about twenty miles from Cumberland, Maryland, during a heavy snowstorm. It was one thirty in the morning, and the temperature outdoors was about 0 degrees Fahrenheit.
