The 'Bombing of Hamamatsu' by Major General Curtis E. LeMay’s US 20th Army Air Force was part of the strategic bombing campaign waged by the USA against Japan’s military and civilian targets and population centres during the Japanese home islands campaign in the closing states of World War II (15 February/29 July 1945).
Hamamatsu was a target for air raids by the US Army Air Forces on several occasions during the Pacific War. In addition to strategic bombing, Hamamatsu was also subjected to tactical air raids launched by US Navy carrierborne warplanes, and was bombarded by US and British warships on 29 July 1945.
In addition to being a major transportation hub on the Tokaido main line railway connecting Tokyo and Osaka, Hamamatsu also had several targets of military significance. It was the location of armaments factories, including Showa Yakuhin, the Nakajima aircraft company and Suzuki motors. It was also the location of the Hamamatsu flight school of the Imperial Japanese army air force and of a major military airfield. Additionally, Hamamatsu was also situated on the main flight route between Saipan in the Mariana islands group and both Nagoya and Tokyo, and was thus often assigned as a secondary target.
In 1945, Hamamatsu had an estimated population of 166,346 persons. One year after the war, the US Army Air Forces’s Strategic Bombing Survey (Pacific War) reported that 60.3% of the city had been totally destroyed.
There were six main attacks on Hamamatsu. On 15 February 1945, 54 Boeing B-29 Superfortress four-engined heavy bombers of the 20th Army Air Force attacked the Mitsubishi motors factory in the southern part of Hamamatsu. Six B-29 bombers were shot down, and 150 people on ground were killed. On 30 April 1945, 69 B-29 bombers delivered a firebombing attack on central Hamamatsu, and an estimated 1,000 civilians were killed. On 14 May 1945, 135 B-29 bombers of Brigadier General Thomas S. Powers’s 314th Bombardment Wing attacked residential areas in the eastern and north-eastern parts of Hamamatsu in a daylight raid, and an estimated 450 civilians were killed. On 19 May 1945, in the course of a follow-on night mission, 32 B-29 bombers of Colonel Douglas C. Polhamus’s 330th Bombardment Group (Very Heavy) bombed the southern area of Nagoya, killing an estimated 450 people. On 18 June 1945, an unknown number of B-29 bombers launched a major firebombing raid on the central areea of Hamamatsu, creating a firestorm which destroyed most of the city; the estimated death toll was 1,800 people. Finally, on 29 July 1945, three US battleships and one British battleship bombarded Hamamatsu, and a follow-on air US raid took place against the recently repaired Hamamatsu railway lines, Hamamatsu station and nearby factories; an estimated 170 people were killed.