Attack on Yokosuka The attack on Yokosuka was an air raid conducted by the United States Navy on 18 July 1945 during the last weeks of the Pacific War . The Japanese battleship " Nagato " was the raid ' s main target , though anti - aircraft positions and other warships at Yokosuka Naval Arsenal were also attacked . Other U . S . Navy and British Royal Navy aircraft struck airfields in the Tokyo area . While " Nagato " was only lightly damaged , the American aircraft sank a destroyer , a submarine and two escort vessels and damaged five small vessels . The Allied pilots also claimed the destruction of several locomotives and 43 Japanese aircraft as well as damage to another 77 aircraft . Japanese anti - aircraft guns shot down twelve American and two British aircraft . Background . During July 1945 the U . S Third Fleet , which was led by Admiral William Halsey , conducted a series of air raids and naval bombardments against targets in Japan . These attacks were made by the Third Fleet ' s striking force , Task Force 38 ( TF 38 ) , which was commanded by Vice Admiral John S . McCain and included nine fleet carriers , six light carriers and their escorts . Almost one thousand aircraft were embarked on board these carriers . On 10 July TF 38 ' s aircraft struck airfields around Tokyo and claimed to have destroyed 340 Japanese aircraft on the ground and two in the air . No Japanese aircraft responded to this attack as they were being held in reserve to mount large - scale suicide attacks on the Allied fleet during the expected invasion of the country later in 1945 . Following this raid , the Third Fleet conducted raids on Hokkaido and northern Honshu on 14 and 15 July which sank large numbers of ships and destroyed 25 aircraft on the ground . The American warships then sailed south and on 16 July were joined by the British Pacific Fleet ' s ( BPF ' s ) main striking force , which was designated Task Force 37 ( TF 37 ) , and comprised three aircraft carriers and their escorts . By July 1945 all of the Imperial Japanese Navy ' s ( IJN ' s ) remaining large warships were unable to put to sea due to shortages of fuel and the dangers of attack from Allied aircraft and submarines . While most of these warships were anchored near the major naval base at Kure and other locations in the Seto Inland Sea , " Nagato " and several smaller warships were stationed at Yokosuka Naval Arsenal in Tokyo Bay . At this time the battleship was moored alongside a pier facing northwest and covered in camouflage that was intended to make her difficult for aircraft to spot . All of " Nagato " s secondary armament and about half her anti - aircraft guns had been removed and emplaced on nearby hills from where they could provide protection to the naval base . Although the battleship ' s boilers were not lit , she received steam and power from the submarine chaser " Fukugawa Maru No . 7 " and an auxiliary boiler located on the pier . The destroyer " Ushio " was also docked nearby in a position where she was able to protect the battleship with her 25 mm anti - aircraft guns . " Nagato " s presence at Yokosuka was revealed to the Allies by photographs taken during the 10 July raid on the Tokyo area . On 16 July Halsey and Vice Admiral Bernard Rawlings , the commander of TF 37 , met to plan raids on the Tokyo area . Halsey was determined to sink the remnants of the IJN , and placed a particularly strong emphasis on attacking " Nagato " as she had been Admiral Isoroku Yamamoto ' s flagship during the attack on Pearl Harbor in December 1941 . Due to the battleship ' s position within a well defended harbor , the Third Fleet ' s planners assessed that aircraft which attempted the straight and level flight needed to launch torpedo es against her would suffer heavy losses , and so decided to use dive bombing tactics instead . As the landward side of the naval base was mountainous , the approaches which could be used by dive bombers were limited , however . Attack . On 17 July the American and British fleet attempted to strike the Yokosuka Naval Arsenal and other targets in the Tokyo area . While two waves of aircraft were dispatched , the attack was frustrated by heavy cloud over the region and further attacks were canceled . The aircraft which reached the Tokyo area struck airfields north of the city and caused little damage . While the naval base was not attacked , it was overflown by an American fighter and its defenders were readied to respond to attacks . On the night of 17 – 18 July American and British warships bombarded the city of Hitachi . The next day , the Allied fleet sailed south looking for weather which was better suited to conducting flight operations . Conditions improved during the morning , and at 11 : 30 am the day ' s air strikes began to launch . The British aircraft of TF 37 were dispatched against airfields in the Tokyo area . The size of this attack was considerably reduced from what was planned , however , as the fuel system on board had become contaminated with water and the carrier could only launch six Vought F4U Corsair fighters . TF 38 ' s main effort was directed against Yokosuka Naval Arsenal , with " Nagato " being designated the raid ' s primary target . A smaller number of American aircraft were also dispatched to raid Japanese air fields . The attack on Yokosuka began at about 3 : 30 pm on 18 July . The first wave of American aircraft attacked the anti - aircraft batteries around the naval base , and succeeded in neutralizing them . Following this , the aircraft of VF - 88 attacked " Nagato " with bombs . A 500 pound general - purpose bomb struck the battleship ' s bridge , killing her commanding officer , Rear Admiral Otsuka Miki as well as the executive officer and at least nine other men . Another 500 pound bomb later struck " Nagato " and detonated near her officer ' s mess , killing about 22 sailors and knocking out four 25 mm guns . The only other direct hit on the ship was made by a shell or rocket which did not explode . In addition , 60 bombs landed in the harbor near " Nagato " , causing breaches to her double hull which let 2 , 000 tons of water into the ship . By the time the attack concluded at 4 : 10 pm , 35 of the battleship ' s 967 officers and men had been killed . The overall damage to the ship was later assessed as being light . American aircraft also attacked several other ships docked at Yokosuka . The unfinished " Matsu " class destroyer " Yaezakura " broke in two and sank after being bombed , and the submarine " I - 372 " was destroyed by another bomb ; at the time the submarine ' s crew was ashore and did not suffer any fatalities . Two escort vessels and a torpedo boat were also sunk . In addition to these losses , five other ships , including the obsolete destroyer " Yakaze " and training ships " Fuji " and " Kasuga " were damaged . Despite their proximity to " Nagato " , " Fukugawa Maru No . 7 " and " Ushio " were not damaged . The British and United States aircraft dispatched against airfields claimed to have destroyed 43 Japanese aircraft and damaged another 77 . The pilots of these aircraft also claimed the destruction of several railway locomotives . Allied losses in the attacks made on 18 July were 12 U . S . Navy aircraft , two Royal Navy aircraft and 18 aircrew . The Allied pilots were disappointed they had not sunk " Nagato " , despite the battleship being the primary target of the raid . Aftermath . Following its attacks on the Tokyo Bay area on 18 July , the Allied fleet sailed away from Japan to be refueled . Its next attacks were made against the main body of the IJN in Kure and the Inland Sea on 24 , 25 and 28 July . These raids sank three battleships , an aircraft carrier and several other warships but cost the Allies 133 aircraft and 102 aircrew killed . The Third Fleet and elements of the BPF continued strikes against targets in Japan until the end of the war on 15 August 1945 . After the attack on Yokosuka , the " Nagato " s crew removed all casualties from the ship and conducted limited repairs . Some of the ship ' s ballast tank s were also flooded to give the impression that she had been sunk . During the early hours of 2 August " Nagato " was ordered to put to sea to intercept an Allied force . However , this sortie was canceled before she had completed preparations to leave port as the report of Allied ships was determined to be false . On 30 August the ship was surrendered to the U . S . Navy . She was one of the target ships for the two atomic bomb tests conducted at Bikini Atoll on 1 and 28 July 1946 during Operation Crossroads , and sank there during the night of 29 – 30 July .