At 15.25 hours on 24 Jan 1942 the Ringstad (Master Jacob K. Knudstad), straggling from convoy ON-55 due to several days of stormy weather, was hit on the starboard side in the foreship by one torpedo from U-333 about 85 miles southeast of Cape Race. All on board abandoned ship in three lifeboats and were questioned by the U-boat that surfaced after the ship sank after 20 minutes by the bow. The Germans offered water and food to the survivors and told them the direction of the nearest land before leaving the area after wishing them good luck.

The lifeboats were separated in the stormy and cold weather. Two lifeboats containing 27 crew members and three passengers were never seen again. Only the motor boat of the master that was completely covered in ice was spotted after five days by an aircraft that escorted a convoy and sent USS Swanson (DD 443) to rescue the master and eleven other survivors in it. The exhausted men were landed at Reykjavik on 5 February.