January 1966: Broken Arrow
A U.S. B-52 bomber carrying nuclear weapons crashes off the coast of Spain. Three hydrogen bombs hit the ground; one falls into the Mediterranean Sea. None of the bombs detonates, and all are eventually recovered, but radioactive plutonium is released on Spanish soil, prompting a massive cleanup effort by the U.S. military. This is just one of scores of incidents described by the U.S. military as "broken arrows" -- lost nuclear weapons.