She was a victim of the Second Happy Time: the Kriegsmarine's Operation Drumbeat to sink Allied merchant shipping in the Western Atlantic On 21 March 1942 British Prudence sailed from Halifax, Nova Scotia carrying 11,500 tons of Admiralty fuel oil bound for St. John's, Newfoundland.

On 22 March the weather worsened with "hail and snow turning to rain, and the wind was south-east, increasing to gale force 7".

Dickson, saw ships in the convoy columns to port and starboard of British Prudence repeatedly converging in heavy seas, so at 2100 hrs.

a torpedo fired by Type VIIC U-boat U-754 hit British Prudence' starboard side amidships, causing extensive damage to No.

In the bow of the ship a fire broke out, fuelled by kerosene barrels and gas cylinders stored in the fo'c's'le.

[3] On 23 March distress messages from the wireless operators on the lifeboats were received, and the W-class destroyer HMS Witherington from troopship convoy NA 006[4] was sent to the area.