With many international observers focused on the Cheonan incident in Korea which killed 46 South Korean sailors, it is a good time to remember another tragedy at sea – and one that has become a pretty much forgotten episode in American history.
On June 8, 1967, the U.S.S. Liberty – a Navy electronic intelligence ship sailing in international waters off the coast of Egypt – was attacked by Israeli planes. The assault killed 34 Americans with many more wounded. The Israelis claimed it was an accident due to the mistaken belief that the ship was an enemy warship. The U.S. government agreed it was an accident.
Whether it was an accident or a deliberate Israeli attack is an on-going debate despite official inquiries on both sides.
For what it is worth (proceed with caution!), here is Wikipedia’s entry: http://en.wikipedia.org/wiki/USS_Liberty_incident.
Note: I am not suggesting the two cases are equivalent. I’m merely remembering an international episode in American history that involved the tragic loss of life at sea.
PILEUS 
If you want a fascinating description of the incident, see the chapter in The Secret War Against the Jews (Joft Loftus).