"Myself, I thought it was probably Egypt," Carpenter said. But the attacking planes and torpedo boats were identified as Israeli.

It was ironic, given the pro-Israel sentiments of much of the Liberty's crew

"We could see the war on the coast. We could see the planes," Carpenter said. "We were cheering the Israelis ... and then they came out and shot at us."

Israel claimed the Liberty was mistaken for an Egyptian vessel. Others have suggested the attack was deliberate. U.S. official reports say the Liberty was flying an American flag.

Now, 45 years later, Carpenter thinks the truth may never be known despite numerous investigations by both sides.

He believes Congress should have held hearings, "but the principals who were involved are all dead," Carpenter said.

"I would have liked to have seen McNamara grilled," Carpenter said. Robert S. McNamara, U.S. defense secretary under Presidents Kennedy and Johnson, died in 2009.

Some have suggested U.S. officials downplayed the incident to preserve relations with Israel --- and may even have been negligent in a military response to support the Liberty.