At 01.54 hours on 31 Aug, 1942, the Jack Carnes was attacked by U-516 with a spread of two torpedoes of which one struck on the starboard side forward of the bridge. The master ordered the helm to be swung to starboard, but the watch below erroneously secured the undamaged engines and the ship lost way. Four minutes after the first hit, the U-boat fired a torpedo which struck on the port side in the #4 tank, followed by a coup de grâce which struck the starboard side amidships. The nine officers, 33 crewmen and 14 armed guards then abandoned ship in two lifeboats. A fifth torpedo was then fired by the U-boat, which struck the starboard side aft of the midships house, a sixth hit the starboard side bunker tanks and a seventh struck amidships. After the last hit, the tanker broke in two and sank, bow rising into the air at 04.26 hours in grid CE 2659.
The survivors set sail together in a southerly direction, but a storm during the night reached gale force and separated the boats. Six days later, the boat with the chief mate, four other officers, four armed guards and 19 crewmen landed on Terceira Island, Azores. The other boat containing the master, three other officers, 14 crewmen and ten armed guards was never seen again.