This is a picture that ought to make us shudder even as we are grateful: it is a Mark39 thermonuclear bomb that came terrifyingly close to detonating on January 24, 1961, when a military aircraft broke up near Goldsboro North Carolina. It was holding a 24-megaton hydrogen bomb, which crashed into a swamp — three of the four triggering mechanisms on the device had been activated. The enriched uranium is still there today. Reports later showed that only one of six safety devices on the bomb had actually worked. Knowledge of this accident strongly influenced American President Kennedy, who afterwards put more strident nuclear safety measures in place.
In fact, the probability of nuclear accidents had been assessed earlier by two mathematicians using Bayesian statistical analysis — a way to apply probability when some information is unknown. This methodology brought the demographic analyst Fred Charles Iklé and statistician Albert Madansky to the terrible but true conclusion that the risk of nuclear bombs accidentally detonating was very possible. These two were largely responsible for putting together a strong proposal to the top military commanders that nuclear weapons needed radical safety measures such as: “requiring at least two people to arm a nuclear weapon; electrifying arming switches to jolt anyone who touched them; arming weapons only over enemy territory; installing combination locks inside warheads; preventing the release of radioactive material in accidental fires of high-energy missile fuels”; and other measures.
The Iklé and Madansky report came out in 1958, but nothing was done about it until after Kennedy took office. Only four days after the new president was inaugurated, the Goldsboro accident happened, and Kennedy was justifiably horrified, and installed more coded locks. Since then, a number of false alarms have happened which could have ended the world had such safety measures not been put in place: aurora borealis, a rising moon, space debris, false US radar signals, and computer errors have all caused alerts.
Of course, the only real security would be complete nuclear disarmament, something we all have a vested interest in.
Sources: Chapter 9 _The Theory That Would Not Die_, Sharon Bertsch Mcgrayne, Yale UP, 2011. National Security Archive Electronic Briefing Book 475, June 9, 2014, “New details on the 1961 Goldsboro Nuclear Accident”
