At 15.13 hours on 23 Nov 1944 the William D. Burnham (Master Emil Rosol) was hit in the stern by one torpedo from U-978 five miles off Barfleur. The ship had missed her rendezvous with convoy TMC-44 and continued alone at 11 knots, escorted by the British armed drifter HMS Fidget (FY 551). The explosion lifted the ship up, blew off the rudder, damaged the propeller, broke the shaft and flooded the #5 hold, causing the ship to settle by the stern. The master ordered the crew to make the lifeboats ready for launching and then tried to save the ship. At 16.06 hours, a FAT coup de grâce struck on the port side in the #3 hold just forward of the bridge and opened a hole of 40 feet in diameter. The explosion also destroyed one of the lifeboats and killed 18 of the 19 men in or near it. The survivors among the eight officers, 33 crewmen, 26 armed guards (the ship was armed with one 4in, one 3in and eight 20mm guns) and one passenger on board abandoned ship in three lifeboats and headed for the beach. Two officers, six crewmen and ten armed guards were lost. The survivors were picked up by the escort vessel and most of them were later transferred to USS PT-461 and landed at Cherbourg, but the last ten survivors (including two injured) were transferred to HMS Vesper (D 55) and taken to Portsmouth.

The badly damaged William D. Burnham was taken in tow by the American tug USS ATR-3, beached at the Grand Roads off Cherbourg and later declared a total loss.