Hi JCRT, I dont know about casualties but in his book 'Hitler's Battleships', Edwyn Grey describes the attack thus; Spearfish's torpedo blew the stern off the Lutzow, disabling her stearing gear and taking both of her propellers off. Lutzow's stern was literally hanging off and the sea was surging into the battleship. Her engines were still turning - minus their props - but Lutzow was sinking slowly by the stern and drifting helplessly towards the Danish coast. Another torpedo would have finnished her off but Spearfish had already turned and ran. Lutzow was experlty kept afloat by her crew until salvage tugs arrived to tow her back into Kiel.