The US has lost three nuclear bombs (possibly six)

Speaking at the time about the dangers of underwater nuclear weapons, Dr Sidharth Kaushal, a research fellow in sea power at the Royal United Services Institute (RUSI), said there was little risk of them being accidentally launched. ‘A pretty valuable [weapon] would be lost or severely damaged,’ he said. ‘This means potentially radioactive waste within the oceans, because it would be very difficult to salvage [the wreck or missile] under those conditions at those depths. But there would be no immediate massive radioactive risks.'