Video: 'The worst naval decision of WW2? - The Destruction of PQ17'

(Friday, July 10, 1942; part of the Second World War, Arctic Campaign) — PQ 17, the code name for an Allied convoy in the Arctic Ocean sailing eastbound from Hvalfjord, Iceland (on June 27, 1942), for the port of Arkhangelsk, Russia, today suffered final losses as German submarine U-251 sank Panamanian freighter El Capitan and German submarine U-376 sank U.S. ship Hoosier in the Barents Sea.

The merchant ships were attacked by Luftwaffe aircraft and U-boats and of the 35 ships, only eleven reached their destination, delivering 70,000 short tons (64,000 metric tons) of cargo.

PQ 17 finally arrived in Russia the following day, on Saturday, July 11, 1942.

Video: 'The World at War: Red Star: The Soviet Union - 1941-1943 (11 of 26)' (PQ 17 at 27:52)

British Prime Minister Winston Churchill called the event, “one of the most melancholy naval episodes in the whole of the war.”

Losses were so heavy that Britain decided to temporarily suspend the lend-lease to the Soviets while the long summer days illuminated the convoys for the German attackers.

The Soviet Union did not believe so many ships could be lost in one convoy and openly accused the Western Allies of lying. Despite the help provided by the material delivered, PQ 17 actually worsened Soviet-Allied relations over the short term, with the Soviets never acknowledging the efforts of Allied merchant seaman or sailors in either navy.