From Wikipedia

Dead In The Water - The Sinking of the USS Liberty

The USS Liberty incident was an attack on a neutral United States Navy technical research ship, USS Liberty, by Israeli jet fighter planes and motor torpedo boats on June 8, 1967, during the Six-Day War. The combined air and sea attack killed 34 crew members (naval officers, seamen, two Marines, and a civilian), wounded 171 crew members, and damaged the ship severely. The ship was in international waters north of the Sinai Peninsula, about 25.5 nautical miles (47.2 km) northwest from the Egyptian city of Arish.

Shortly after the attack ended, Israel informed the U.S. that its forces had attacked the Liberty in error—a friendly fire incident. An Israeli inquiry by Colonel Ram Ron concluded that the attack was caused by a chain of mistakes by Israel Defense Force (IDF) personnel. The IDF, in its History Report about the attack, says that an IAF (Israel Air Force) 'Nord' reconnaissance aircraft discovered a ship approaching the war-zone area, during early morning hours. A marker for the ship's location was placed on an IDF control table. The ship was eventually identified as USS Liberty. At about 1100 (local time), the Liberty's marker was removed from the control table because the ship's current location was unknown. During the attack, the IDF air and naval forces, respectively, misidentified the Liberty as an unknown destroyer and the Egyptian cargo ship El Quseir.