The RAF repeatedly made large attacks against Brest that targeted the German battleships. The first raid took place on the night of 30/31 March. On 6 April a British aircraft torpedoed "Gneisenau". She was hit by four bombs during another raid on 10 April. It took until the end of 1941 for the damage inflicted in these two attacks to be repaired. "Scharnhorst" required repairs to her boilers which rendered her unable to participate in Operation Rheinübung, the raid into the Atlantic undertaken by "Bismarck" and "Prinz Eugen", during May. Lütjens led this raid, and sank HMS "Hood" on 24 May. He was killed when "Bismarck" was destroyed by the Home Fleet on 27 May. Guided by Ultra intelligence, the British also sank seven of the eight supply ships that had been sent into the Atlantic to support "Bismarck". Following this defeat Hitler forbade further battleship raids into the Atlantic. On 13 June RAF aircraft torpedoed the cruiser Lützow which was trying to break out into the Atlantic. This was the final attempt by the to send heavy warships into the Atlantic. Submarines were the main element of the German anti-shipping campaign for the remainder of the war.