http://www.cnn.com/2004/US/09/13/lost.bomb/index.html
The United States lost 11 nuclear bombs in accidents during the Cold War that were never recovered, according to the Brookings Institution, a Washington think tank.
An estimated 50 nuclear warheads, most of them from the former Soviet Union, still lie on the bottom of the world's oceans, according to the environmental group Greenpeace.
One of the most celebrated accidents took place over Palomares, Spain, in January 1966 when a U.S. B-52 collided with a KC-135 tanker during midair refueling and released all four of its hydrogen bombs in the ensuing explosion. Seven of the 11 crewmen aboard both planes were killed.
The high explosive igniters on two bombs detonated on impact, spreading radioactive material, including plutonium, over a wide area of the Spanish countryside. A third bomb landed relatively intact and was recovered.
The fourth bomb landed in the Mediterranean Sea, and U.S. military searchers took nearly three months to find and recover the device intact.
The Spanish recovery, clean up, and legal settlements cost us $182 million in 1966 dollars.
Maybe we ought to leave this one lost.