 The 1st Mobile Fleet was en route to Guimares Island in the central Philippines on 13 June , where they intended to practice carrier operations in an area better protected from submarines , when Vice Admiral Jisaburō Ozawa learned of the American attack on the Mariana Islands the previous day . Upon reaching Guimares , the fleet refueled and sortied into the Philippine Sea where they spotted Task Force 58 on 18 June . At this time , the sister ships mustered 54 Zeros , 60 D4Ys and 36 Nakajima B6N " Jill " torpedo bombers . As the carriers were launching their first airstrike the following morning , Taihō was torpedoed by an American submarine and later sank . Later that morning , Shōkaku was torpedoed by a different submarine , USS Cavalla . The three or four torpedoes started multiple fires in the hangar , which ignited fueling aircraft , in addition to causing heavy flooding . As the bow continued to sink , aircraft and munitions began to slide forward and a bomb in the hangar detonated . This ignited gas and oil fumes which caused a series of four explosions that gutted the ship . Shōkaku sank several minutes later with the loss of 1 @,@ 263 of her crew . 570 men were rescued by a light cruiser and a destroyer . 
