 On 14 May 1904 , Admiral Nashiba put to sea with the battleships Hatsuse ( flag ) , Shikishima , and Yashima , the protected cruiser Kasagi , and the dispatch boat Tatsuta to relieve the Japanese blockading force off Port Arthur . On the following morning , the squadron encountered a minefield laid by the Russian minelayer Amur . Hatsuse struck one mine that disabled her steering at 10 : 50 a.m. and Yashima struck another when moving to assist Hatsuse . At 12 : 33 p.m. , the latter drifted onto another mine that detonated one of her magazines , killing 496 of her crew , and sinking the ship at 38 ° 37 ′ N 121 ° 20 ′ E. Tatsuta and Kasagi managed to save the Admiral and Captain Nakao with 334 other officers and enlisted men . Yashima 's flooding could not be controlled and she foundered about eight hours later , after her crew had abandoned ship . 
