1. Nuclear Bombs
During the Cold War there was a mass effort by both the US and the Soviet Union to produce and test nuclear weapons. Part of the testing of nuclear bombs involved bombers flying
long distance flights over Greenland, Europe and Asia. Before the US developed the capability of long distance flights without refueling there were several midair collisions and accidents. As these aircraft routinely carried nuclear weapons,
some bombs were lost in oceans. Officially there are 11 missing nuclear bombs, but others estimate as many as 50 may be missing. However it is not just nuclear bombs that can go missing. The nuclear codes used by the President Clinton to launch a nuclear attack
went missing for several months. Although it is likely that the President was unaware that the codes had disappeared as it was usual for aids to keep the codes safe.