Complex sentence: Underwater, the Americans fired a spread of torpedoes and one struck the U-boat which had a Japanese flag painted on the side, it sank quickly at position with 54 men still aboard, including "Kapitänleutnant" (Lieutenant Commander) Fritz Schneewind.
Split into simpler sentences: Underwater, the Americans fired a spread of torpedoes and one struck the U-boat which had a Japanese flag painted on the side. The German submarine sank quickly at position with 54 men still aboard, including "Kapitänleutnant" (Lieutenant Commander) Fritz Schneewind.