Loosestrife sailed with Convoy ONS 5 (outward, northbound, slow) from Britain to North America in 1943. The convoy was made up of 42 ships, of which 12 or 13 were sunk after the convoy came under sustained attack from German submarines hunting in packs.[3] On 5 May at 02:25, Bristol City was south of Greenland and east of Newfoundland when it was sunk by a torpedo fired by the German submarine U-358, under the command of Rolf Manke. Fifteen of the 44 people on board died.[4] Manke attacked and damaged Wentworth not long after. Loosestrife rescued survivors from both sinkings and landed them at St. Johns in Newfoundland.[5][6][7]