Operation Bombing of Kumagaya

The 'Bombing of Kumagaya' by Major General Curtis E. LeMay’s US 20th Army Air Force was part of the strategic bombing campaign waged by the USA against military and civilian targets and population centres during the Japanese home islands campaign in the closing stages of World War II (14/15 August 1945).

Although the Japanese government had already agreed to accept the terms of the Potsdam Declaration and unconditionally surrendered to the Allies on 14 August, the USAAF had already launched another bombing mission against the Japanese cities of Isesaki, Gunma and Kumagaya in the Saitama prefecture, and would not call off the raid as the surrender has not yet been officially accepted by the US government. The crews of Brigadier General Thomas S. Power’s 314th Bombardment Wing were aware that the war was all but over, and in the words of a New York Herald Tribune correspondent, no one wanted to die over a target that was 'a pathetically small city of little obvious importance'.

At this time, Kumagaya lacked major targets of military significance, except for the manufacture of some components for the Nakajima aircraft company and the Imperial Japanese army’s Kumagaya air academy. The city had an estimated population of 45,000.

On 14 August 1945, 77 Boeing B-29 Superfortress four-engined heavy bombers of the 314th Bombardment Wing and 16 B-29 bombers of the 313th Bombardment Squadron took off from bases on Guam in the Mariana islands group. The lead aircraft carried six 1,000-lb (454-kg) high explosive bombs fused for an air burst over the city: the intent was that the city’s inhabitants would then seek shelter underground before the remaining aircraft attacked in a box-pattern from all sides to incinerate the trapped civilians. In addition, it was hoped that the noise of the explosion would be so great that the Japanese authorities would believe that the city had been annihilated by a nuclear weapon.

Four aircraft were forced to abort with mechanical problems, and the remaining 89 aircraft arrived over target at 00.23 on 15 August in clear weather. Bombing continued to 01.39 from an altitude of 14,000 to 17,000 ft (4265 to 5180 m) with 356 M17, 1,372 M19 and 6,321 M47 incendiary bombs. The total tonnage was more than three times the average tonnage dropped on other Japanese cities during the war.

The Japanese made no resistance, and all attacking aircraft returned safely, with five aircraft diverting to Iwo Jima island as a result of mechanical issues.

The resulting firestorm destroyed most of Kumagaya, with 74% of the city area destroyed. This included 3,630 structures, or 40% of the city’s buildings. The casualties included 266 civilian dead and more than 3,000 injured, or approximately 28% of the city’s population.

Emperor Hirohito’s Gyokuon-hoso (broadcast in the Emperor’s voice), the imperial rescript, confirming Japan’s acceptance of the Potsdam Declaration was made between 12.00 and 12.04 on 15 August, and World Ear II came to an end.