At 15.33 hours on 5 March 1942 the unescorted O.A. Knudsen (Master Knut O. Bringedal) was hit on the port side in tank #6 by one torpedo from U-128 east of Abaco Island, Bahamas. The ship started listing and the engines were stopped. The crew abandoned ship in the starboard lifeboat and a motorboat, but eight men remained on board, managed to restart the engines and head for land. A first coup de grâce at 15.42 hours missed, but a second fired at 16.42 hours hit on the port side in tank #9, killing a British deck boy. The remaining men abandoned ship in the port lifeboat and the master ordered the starboard lifeboat containing 24 men to head for nearest land, while the motorboat and the port lifeboat stayed near the ship.

The master and four crew members then reboarded the tanker, rigged up a new antenna and managed to establish a radio contact with a land station. They also transferred some petrol to the motorboat and abandoned the vessel. At 02.30 hours on 6 March, the master and six crewmen again reboarded the O.A. Knudsen in order to save the vessel. 15 minutes later, U-128 began shelling the tanker, which caught fire and eventually sank. The master and five men had been injured by shrapnel during the shelling before they were able to leave the ship with the motorboat. In the evening, they spotted the starboard lifeboat and took it in tow. Land was reached in the night, but they gave up trying to find a suitable landing place. On 7 March, the boats were taken in tow by a schooner, which landed them at Cornwall, Abaco Island. On 10 March, an able seaman died of wounds in a hospital and was buried on Abaco Island.