This was a US air attack on Tokyo using incendiary rather than HE bombs (9/10 March 1945).
The first air raid by the USAAF on Tokyo had been the so-called ‘Doolittle raid’ (more formally ‘Conceal’) of 18 April 1942 when 16 North American B-25 Mitchell bombers lifted off the flight deck of the fleet carrier Hornet to bomb targets, including Yokohama and Tokyo, and then fly on to airfields in China. The raids were a significant propaganda victory. Launched prematurely, none of the bombers reached the designated airfields, and therefore had to crash or ditch, the sole exception being one aeroplane which landed in the USSR, where its crew was interned. Two crews were captured by the Japanese.
The decisive element in the US concept of taking the strategic air war to Japan was the creation of the Boeing B-29 Superfortress heavy bomber, which had an operational radius of 1,500 miles (2415 km) with its maximum bomb load: almost 90% of the bombs eventually dropped on the Japanese home islands were delivered by the B-29, amounting to some 130,900 tons.
The first raids were carried out, in ‘Matterhorn’, by Brigadier General Kenneth B. Wolfe’s (later Major General Curtis E. LeMay’s) XX Bomber Command of the 20th AAF operating from bases in China, but the campaign began to reach an operational maturity with the activation of the same air force’s XXI Bomber Command, under Brigadier General Haywood S. Hansell (later LeMay) from the airfields of the Mariana islands group from November 1944. The B-29 bomber units of the XX Bomber Command were transferred to join the XXI Bomber Command during spring 1945, and were based on Guam. The 20th AAF was commanded directly by General Henry H. Arnold, commander of the USAAF, to prevent control of US strategic air power against the Japanese falling into the control of Admiral Chester W. Nimitz or General Douglas MacArthur, commanding the Pacific Ocean Areas and South-West Pacific Area respectively. Arnold was not fully fit, however, after suffering four heart attacks, and on 16 July 1945 allocated command of the 20th AAF to LeMay.
The services reached a compromise on unity of command issues with the Joint Chiefs-of-Staff, which included Arnold, by a retention of the strategic air forces through a new command, General Carl A. Spaatz’s Strategic Air Forces in the Pacific, LeMay becoming Spaatz’s chief-of-staff on 2 August 1945, and the 20th AAF then coming under the command of Lieutenant General Nathan F. Twining.
It was on 15 June 1944 that China-based B-29 bombers had undertaken their first raid on targets in Japan, the aircraft taking off from Chengdu, more than 1,500 miles (2415 km) distant from their objectives. This first raid was only very partially effective: just 47 out of 68 B-29 bombers attacked the designated target area, four aircraft aborted with mechanical problems, four crashed, six jettisoned their bombs because of mechanical difficulties, and the other seven bombed secondary targets or targets of opportunity. Only one B–29 was lost to Japanese air attack.
The first raid from the Mariana islands group was delivered on 24 November 1944, when 88 aircraft bombed Tokyo. The bombs were dropped from an altitude of about 30,000 ft (9145 m), and it is estimated that only some 10% of the weapons hit their targets as a result of the difficulty of bomb aiming in the presence of cloud and of the effects of differing wind speeds and vectors on the bombs as they fell.
The bombing effort from the mainland of China was never satisfactory as the Chinese bases were difficult to supply via the ‘hump’ of the eastern Himalayas from India, and the B-29 bombers operating from these bases could reach Japan only by operating with reduced bomb loads so that the free weapons bay volume could be devoted to additional fuel tankage.
When Nimitz’s ‘island-hopping’ campaign through the Central Pacific captured islands within effective B-29 range of Japan, as noted above the 20th AAF assumed control of the XXI Bomber Command based on Guam, Saipan and Tinian islands in the Mariana islands group. From the great base complexes quickly created on these three islands the bombers could now deliver maximum bomb loads. As in Europe, the USAAF initially adopted the tactic of precision bombing by daylight. This proved to be very ineffective because of the wind conditions typical of Japan: bombs dropped from high altitude were destabilised by high winds as they fell, and accuracy was therefore all but impossible.
LeMay therefore switched his aircraft to massed night attacks, in which bombs were released at altitudes ranging from 5,000 to 7,000 ft (1525 to 2135 m), and using incendiaries rather than HE bombs in reflection that wood and other flammable material predominated in the construction of Japanese urban areas. Thus fire-bombing raids were made on the primary Japanese conurbations, these including Tokyo, Nagoya, Osaka and Kobe. Despite limited early success, LeMay was determined to continue the use of such bombing tactics against the vulnerable Japanese cities. Attacks on strategic targets also continued in lower-level daylight raids, often with HE bombs to destroy the concrete beds on which equipment such as machine tools were bedded.
The first fire-bombing raid was that flown against Kobe on 3 February 1945, and following its relative success the USAAF continued the use of the new tactic. Japanese cities were generally susceptible to such attack, but the most favourable conditions for success were areas with few firebreaks and high surface winds. In the absence of effective Japanese anti-aircraft fire and night fighters, much of the bombers’ defensive armour and self-protection weapons were also removed to allow increased bomb loads, but ultimately loads were increased by the use of low altitudes for fuel conservation, with individual aircraft bomb loads increasing from 5,200 lb (2360 kg) per aeroplane in March to 14,600 lb (6625 kg) in August.
The first fire-bombing attack on Tokyo was flown on the night of 23/24 February, when a force of 174 B-29 bombers destroyed about 1 sq mile (2.59 km²) of the city.
In the evening of 9 March some 334 B-29 bombers took off from the bases on the Mariana islands group, formed and headed for Tokyo. Some 279 of the bombers attacked, and these dropped 1,665 tons of bombs, comprising mostly 500-lb (227-kg) E46 cluster bombs each containing 38 napalm-filled M69 bomblets, but also numbers of 100-lb (45-kg) M47 jellied petrol and white phosphorus incendiary bombs, from altitudes between 2,000 to 2,500 ft (610 and 760 m).
In the raid’s first two hours, 226 of the bombers dropped their bombs to overwhelm the city’s fire defences. The first B-29 aircraft to arrive dropped bombs in a large X pattern centred on Tokyo’s densely populated working class district near the docks in both the Koto and Chuo city wards, and later aircraft simply aimed at this brightly burning X pattern. 'Meeting House' lost 14 B-29 bombers.
The individual fires caused by the bombs quickly joined to create a general conflagration, which would have been classified as a firestorm but for prevailing winds gusting at 17 to 28 mph (27 to 45 km/h).
The fires were so hot they ignited the clothing on individuals as they tried to flee. Many women were wearing what were called ‘air-raid turbans’ around their heads and the heat ignited these like a wick on a candle. It is believed that the Japanese death toll was in the order of 100,000 persons, so this may have been the most devastating single raid ever carried out by aircraft, not excluding the 'Silverplate' and 'Centerboard' atomic bombings of Hiroshima and Nagasaki, and the firebombing of Dresden. About 15.8 sq miles (40.92 km²) of the city were destroyed, the destruction and damage being worst in the areas of the city to the east of the Imperial Palace.
The damage to Tokyo’s heavy industry had been relatively slight until firebombing destroyed much of the light industry used as an integral source for small machine parts and time-intensive processes. Fire bombing also killed or made homeless many workers who involved in war industries. More than 50% of Tokyo’s industry was spread out among residential and commercial neighbourhoods, and fire bombing cut the output of the entire city by 50%.
In the following two weeks there were almost 1,600 further sorties against Tokyo, Nagoya, Osaka and Kobe, destroying 31 sq miles (80.3 km²) in total at a cost of a mere 22 aircraft. A third fire-bomb raid was flown against Tokyo on 26 May, and it is worth noting that the incendiary attacks were interspersed with more conventional raids using HE bombs.
With the capture of Okinawa and the end of the war with Germany, the 8th AAF was transferred from the UK to this large island, and began its own raids under the command of Lieutenant General James H. Doolittle. The monthly tonnage dropped on Japan had increased from 12,320 tons in March to 38,125 tons in July, and an increase to 102,680 tons was planned but not implemented as the war ended. Tokyo was never seriously considered as a target for an atomic bombing, although consideration was given to the detonation of such a weapon in Tokyo Bay in a non-lethal demonstration.