Sinking was an accident.

During the Six Day War in 1967, Israel bombed an American spy ship called the USS Liberty, sinking it, and killing a number of American servicemen.

Israel apologized almost immediately, stating that they believed the ship to be Egyptian, and paid compensation to the families of the servicemen, but conspiracy theorists have, for years, insisted that Israel knowingly attacked a U.S. ship.

The United States National Security Agency this week released transcripts of conversations between the Israeli pilots and their base, which were recorded by an NSA spy plane at the time. The transcripts bear out Israel's version of the story.

Only at 3:07 were the pilots first informed that the ship might not have been Egyptian at all: Hatzor told them that if they found Arabic-speaking survivors, they should be taken to El-Arish, but if they found English-speaking survivors, they should be taken to Lod. "Clarify by the first man that you bring up, what nationality he is, and report to me immediately," the supervisor instructed, according to the transcript. "It's important to know."

Thanks to Bernsteinblog for the pointer.

Update: The NSA has released the audio and transcripts on their website.