Answer:
The German Type VIIB U-Boat U-55, under the command of Kapitanleutnant Werner Heidel, was sunk by British and French warships and a British air strike 90 miles SW of the Isles of Scilly (English Channel), coordinates 48.37N, 07.48W, on January 30, 1940.
Though credited with sinking 6 Allied ships, she was sunk on her first and only war patrol. There were 41 survivors and 1 KIA, Heidel, who apparently went down with his boat after getting his crew to safety. Unlike many other U-Boats, the U-55 did not suffer any crew accidents/casualties until she was sunk, making her a rarity in the U-boat fleet.
Source Credit: U-Boat.net (see link below)