Is it the occasion in the last war when a U-Boat sank one of the Union-Castle ships off West Africa and there were hundreds of Italian p.o.w.'s aboard . The U-Boat surfaced to try and take a senior officer prisoner and then discovered the enormity of her sinking. Doenitz agreed to a rescue operation involving German and Italian submarines which was going quite well until a squadron of U.S.A.A.F., Mitchell bombers spotted these submarines with life-boats in tow and others on the casing and bombed them. The americans claimed not to have picked up the #En Clear' message sent by the U-Boat saying what they were trying to do. Tow them to Senegal which was Vichy of course. Can't remember the Union boat's name nor the U-Boat's number. The foregoing is what I can recollect though.
It is difficult to be 100% sure by looking at this photo.
Stumps you are refering to the LACONIA incident. The ship was torpedoed by Werner Hartenstein commanding U-156. The US pilots actions had far reaching consequences for merchantmen for the rest of the war.