The Liberty ship William Dawes was built by the Oregon Shipbuilding Company and operated by Weyerhaeuser Steamship Company, she was delivered on April 1, 1942. On July 22, 1942 she was in the Tasman Sea en route to the combat zone in the Pacific with a cargo of munitions, trucks, jeeps and other vehicles badly needed by Allied forces. She had stopped in Adelaide and was due to stop in Sydney and Brisbane before her final destination, but while making her way way along the coast of New South Wales the lone ship was found by I-11.

The first torpedo struck in the stern just before dawn, the explosion caused the stern to separate. The engine room and other compartments flooded and the order to abandon ship came shortly thereafter. The attack killed five men, four U.S. Navy Armed Guards and one U.S. Army passenger, but the remaining fifty-four managed to get off the ship in the lifeboats.

Seaman 2nd Class Bill Minton, one of the survivors relates his experience;

"I was off watch and asleep in my bunk when it struck. All the killed and wounded were in or on the after deck house which took the first torpedo. With the after section essentially severed from the main hull and electrical connections broken it was a pitch black mess in the compartments. The portholes and the hatch had been dogged down, the port side hatch by this time was under water with the starboard hatch the only way out. It was apparently somewhat sprung which made the dogs very stubborn. I was the first there and wasn't making much headway until George Avant showed up. With the two of us working we finally got the hatch open with very little time to spare. 

Two others made it out behind us before the section completely separated and sunk. Three others didn't. Dave Hogan and Cpl. Cable were on watch on the gun deck and must have been killed by the initial blast. We made way to the boat deck and got into a lifeboat."

An hour after the first attack a second torpedo slammed into the ship which caused more explosions and fires. The burning ship sank sometime late that afternoon. According to Minton "the sub surfaced when we were in the lifeboats. The I-11 was  type A1 that had a airplane hangar forward of the conning tower. It was a huge sub, and we couldn't believe our eyes when she surfaced. It looked as big as the liberty she we had just left.  Actually it was a scant 50 feet shorter".

The survivors were quickly found by local trawlers sent by the Merimbula police and towed to that port. Those who were wounded were treated at a local hospital and the remainder were boarded in the homes of willing local residents. Minton was one of the wounded;

"I spent six weeks in the Pambula District Hospital, the last four weeks I was the only Yank. I can't say enough about the friendliness and hospitality of the residents. I have carried a warm spot in my heart since for the people of Merimbula and Pambula in particular and for Australia in general".

I-11 survived until sometime between January 11 and March of 1944, a signal was sent on Jan. 11 from near Funafuti, in the Ellice islands and the boat was never heard from again.