Bombing of Tokyo (10 March 1945)

On the night of 9/10 March 1945, the United States Army Air Forces (USAAF) conducted a devastating firebombing raid on Tokyo, the Japanese capital city. This attack was code-named Operation Meetinghouse by the USAAF and is known as the Great Tokyo Air Raid in Japan. Bombs dropped from 279 Boeing B-29 Superfortress heavy bombers burned out much of eastern Tokyo. More than 90,000 and possibly over 100,000 Japanese people were killed, mostly civilians, and one million were left homeless, making it the most destructive single air attack in human history. The Japanese air and civil defenses proved largely inadequate; 14 American aircraft and 96 airmen were lost.

The attack on Tokyo was an intensification of the air raids on Japan which had begun in June 1944. Prior to this operation, the USAAF had focused on a precision bombing campaign against Japanese industrial facilities. These attacks were generally unsuccessful, which contributed to the decision to shift to firebombing. The operation during the early hours of 10 March was the first major firebombing raid against a Japanese city, and the USAAF units employed significantly different tactics from those used in precision raids, including bombing by night with the aircraft flying at low altitudes. The extensive destruction caused by the raid led to these tactics becoming standard for the USAAF's B-29s until the end of the war.

There has been a long-running debate over the morality of the 10 March firebombing of Tokyo. The raid is often cited as a key example in criticism of the Allies' strategic bombing campaigns, with many historians and commentators arguing that it was not acceptable for the USAAF to deliberately target civilians, and other historians stating that the USAAF had no choice but to change to area bombing tactics given that the precision bombing campaign had failed. It is generally acknowledged that the tactics used against Tokyo and in similar subsequent raids were militarily successful. The attack is commemorated at two official memorials, several neighborhood memorials, and a privately run museum.

Background

Pre-war USAAF doctrine emphasized the precision bombing of key industrial facilities over area bombing of cities. Early American strategic bombing attacks on Germany used precision tactics, with the bomber crews seeking to visually identify their targets. This proved difficult to achieve in practice. During the last 20 months of the war in Europe, non-visual attacks accounted for about half of the American strategic bombing campaign against Germany. These included major area bombing raids on Berlin and Dresden, as well as attacks on several towns and cities conducted as part of Operation Clarion. The American attacks on Germany mainly used high-explosive bombs, with incendiary bombs accounting for only 14 percent of those dropped by the Eighth Air Force. The British Bomber Command focused on destroying German cities from early 1942 until the end of the war, and incendiaries represented 21 percent of the tonnage of bombs its aircraft dropped. Area bombing of German cities by Allied forces resulted in the deaths of hundreds of thousands of civilians and massive firestorms in cities such as Hamburg and Dresden.

Japanese forces conducted area bombing attacks on Chinese cities throughout the war. Few attempts were made to target industrial facilities, with the goal of the campaign being to terrorize civilians and cut the Chinese forces off from their sources of supplies. Chongqing, China's provisional capital, was frequently attacked by aircraft using incendiary and high explosive bombs. These raids destroyed most of the city.

The American Doolittle Raid on 18 April 1942 was the first air attack on Tokyo, but inflicted little damage on the city. In June 1944 the USAAF's XX Bomber Command began a campaign against Japan using B-29 Superfortress bombers flying from airfields in China. Tokyo was beyond the range of Superfortresses operating from China, and was not attacked. This changed in October 1944, when the B-29s of the XXI Bomber Command began moving into airfields in the Mariana Islands. These islands were close enough to Japan for the B-29s to conduct a sustained bombing campaign against Tokyo and most other Japanese cities. The first Superfortress flight over Tokyo took place on 1November, when a reconnaissance aircraft photographed industrial facilities and urban areas in the western districts of the city. The remainder of Tokyo was photographed in subsequent reconnaissance flights, and these images were used to plan the 10 March raid and other attacks on urban areas.

The overall plan for the strategic bombing campaign against Japan specified that it would commence with precision bombing raids against key industrial facilities, and later include firebombing attacks on cities. The first target directive issued to the XXI Bomber Command by its parent unit, the Twentieth Air Force, on 11 November, 1944 specified that the main target was Japanese aircraft and aviation engine factories. These targets were to be attacked by precision bombing. Japanese cities were specified as the secondary target, with area bombing being authorized for use against them. The directive also indicated that firebombing raids were likely to be ordered against cities to test the effectiveness of this tactic. The Twentieth Air Force had an unusual command structure, as it was personally headed by General Henry H. Arnold, the commanding officer of the USAAF.

B-29 raids on Tokyo commenced on 24 November. The first raid targeted an aircraft engine factory on the city's outskirts, and caused little damage. XXI Bomber Command's subsequent raids on Tokyo and other cities mainly used precision bombing tactics and high explosive bombs, and were largely unsuccessful due to adverse weather conditions and a range of mechanical problems which affected the B-29s. These failures led to the head of the Command being relieved in January 1945. Major General Curtis LeMay, the commander of XX Bomber Command, replaced General Hansell. Arnold and the Twentieth Air Force's headquarters regarded the campaign against Japan up to that time as unsuccessful, and LeMay understood that he would also be relieved if he failed to deliver results. He believed that changing the emphasis from precision bombing to area bombing was the most promising option to turn the XXI Bomber Command's performance around.

Preparations

Early incendiary raids on Japan

USAAF planners began assessing the feasibility of a firebombing campaign against Japanese cities in 1943. Japan's main industrial facilities were vulnerable to such attacks as they were concentrated in several large cities, and a high proportion of production took place in homes and small factories in urban areas. The planners estimated that incendiary bomb attacks on Japan's six largest cities could cause physical damage to almost 40 percent of industrial facilities and result in the loss of 7.6 million man-months of labor. It was also estimated that these attacks would kill over 500,000 people, render about 7.75 million homeless and force almost 3.5 million to be evacuated. The plans for the strategic bombing offensive against Japan developed in 1943 specified that it would transition from a focus on the precision bombing of industrial targets to area bombing from around halfway in the campaign, which was forecast to be in March 1945.

Preparations for firebombing raids against Japan began well before March 1945. In 1943 the USAAF tested the effectiveness of incendiary bombs on adjoining German and Japanese-style domestic building complexes at the Dugway Proving Ground. These trials demonstrated that M69 incendiaries were particularly effective at starting uncontrollable fires. These weapons were dropped from B-29s in clusters, and used napalm as their incendiary filler. After the bomb struck the ground, a fuse ignited a charge which first sprayed napalm from the weapon, and then ignited it. Prior to March 1945, stockpiles of incendiary bombs were built up in the Mariana Islands. These were accumulated on the basis of XXI Bomber Command plans which specified that the B-29s would each carry of the weapons on 40 percent of their monthly sorties. Arnold and the Air Staff wanted to wait to use the incendiaries until a large-scale program of firebombing could be mounted, to overwhelm the Japanese city defenses.

Several raids were conducted to test the effectiveness of firebombing against Japanese cities. A small incendiary attack was made against Tokyo on the night of 29/30 November 1944, but caused little damage. Incendiaries were also used as part of several other raids. On 18 December 84 XX Bomber Command B-29s conducted an incendiary raid on the Chinese city of Hankou which caused extensive damage. That day, the Twentieth Air Force directed XXI Bomber Command to dispatch 100 B-29s on a firebombing raid against Nagoya. An initial attack took place on 22 December which was directed at an aircraft factory and involved 78 bombers using precision bombing tactics. Few of the incendiaries landed in the target area. On 3January, 97 Superfortresses were dispatched to firebomb Nagoya. This attack started some fires, which were soon brought under control by firefighters. The success in countering the raid led the Japanese authorities to become over-confident about their ability to protect cities against incendiary attacks. The next firebombing raid was directed against Kobe on 4February, and bombs dropped from 69 B-29s started fires which destroyed or damaged 1,039 buildings.

On 19 February the Twentieth Air Force issued a new targeting directive for XXI Bomber Command. While the Japanese aviation industry remained the primary target, the directive placed a stronger emphasis on firebombing raids against Japanese cities. The directive also called for a large-scale trial incendiary raid as soon as possible. This attack was made against Tokyo on 25 February. A total of 231 B-29s were dispatched, of which 172 arrived over the city; this was XXI Bomber Command's largest raid up to that time. The attack was conducted in daylight, with the bombers flying in formation at high altitudes. It caused extensive damage, with almost 28,000 buildings being destroyed. This was the most destructive raid to have been conducted against Japan, and LeMay and the Twentieth Air Force judged that it demonstrated that large-scale firebombing was an effective tactic.

The failure of a precision bombing attack on an aircraft factory in Tokyo on 4March marked the end of the period in which XXI Bomber Command primarily conducted such raids. Civilian casualties during these operations had been relatively low; for instance, all the raids against Tokyo prior to 10 March caused 1,292 deaths in the city.

Preparations to attack Tokyo

In early March, LeMay judged that further precision bombing of Japanese industrial targets was unlikely to be successful due to the prevailing weather conditions over the country. There were on average only seven days of clear skies each month, and an intense jet stream made it difficult to aim bombs from high altitudes. Due to these constraints, LeMay decided to focus XXI Bomber Command's attacks on Japanese cities. While he made this decision on his own initiative, the general directions issued to LeMay permitted such operations. On 5March XXI Bomber Command's personnel were advised that no further major attacks would be scheduled until 9March. During this period LeMay's staff finalized plans for the attack on Tokyo. At a meeting on 7March, LeMay agreed to conduct an intense series of raids against targets on the island of Honshu between 9and 22 March as part of the preparations for the invasion of Okinawa on 1April.

LeMay decided to adopt radically different tactics for this campaign. Analysis by XXI Bomber Command staff of the 25 February raid concluded that the incendiary bombs had been dropped from too high an altitude, and attacking at lower levels would both improve accuracy and enable the B-29s to carry more bombs. This would also expose them to the Japanese air defenses, but LeMay judged that poor Japanese fire control tactics meant that the additional risk was moderate. As weather conditions over Japan tended to be more favorable at night and the LORAN systems the B-29s used to navigate were more effective after dusk, it was also decided to conduct the attack at night. This led to a decision to direct the aircraft to attack individually rather than in formations as it was not possible for the B-29s to keep station at night. Flying individually would also lead to reductions in fuel consumption as the pilots would not need to constantly adjust their engines to remain in formation. These fuel savings allowed the Superfortresses to carry twice their usual bomb load. USAAF intelligence had determined that the Japanese had only two night fighter units, and these were believed to pose little threat. As a result, LeMay decided to remove all of the B-29s' guns other than those at the rear of the aircraft to reduce the weight of the aircraft and further boost the weight of bombs they could carry. While LeMay made the ultimate decision to adopt the new tactics, he acknowledged that his plan combined ideas put forward by many officers. On 7March, some of the B-29 crews flew training missions in which they practiced using radar to navigate and attack a target from low altitude. The airmen were not told the purpose of this training.

The officers who commanded XXI Bomber Command's three flying wings agreed with the new tactics, but there were fears that they could result in heavy casualties. These concerns were shared by some of LeMay's staff. XXI Bomber Command's intelligence officers predicted that 70 percent of the bombers could be destroyed. LeMay consulted Arnold's chief of staff Brigadier General Lauris Norstad about the new tactics, but did not formally seek approval to adopt them. He later justified this action on the grounds that he had wanted to protect Arnold from blame had the attack been a failure. LeMay notified the Twentieth Air Force headquarters of his intended tactics on 8March, a day he knew Arnold and Norstad would be absent. There is no evidence that LeMay expected that the Twentieth Air Force would object to firebombing civilian areas, but he may have been concerned that it would have judged that the new tactics were too risky.

Japanese defenses

The Japanese military anticipated that the USAAF would make major night attacks on the Tokyo region. After several small night raids were conducted on the region during December 1944 and January 1945, the Imperial Japanese Army Air Force's 10th Air Division, which was responsible for intercepting attacks on the Kantō region, placed a greater emphasis on training its pilots to operate at night. One of the division's flying regiments (the 53rd Air Regiment) was also converted to a specialized night fighter unit. On the night of 3/4 March, the Japanese military intercepted American radio signals which indicated that the XXI Bomber Command was conducting a major night flying exercise. This was interpreted to mean that the force was preparing to start large-scale night raids on Japan. However, the Japanese did not expect the Americans to change to low altitude bombing tactics.

The military forces assigned to protect Tokyo were insufficient to stop a major raid. The Eastern District Army's Kanto Air Defense Sector was responsible for the air defense of the Tokyo region, and was accorded the highest priority for aircraft and antiaircraft guns. The 1st Antiaircraft Division controlled the antiaircraft guns stationed in the central region of Honshu, including Tokyo. It was made up of eight regiments with a total of 780 antiaircraft guns, as well as a regiment equipped with searchlights. American military intelligence estimated that 331 heavy and 307 light antiaircraft guns were allocated to Tokyo's defenses at the time of the raid. A network of picket boats, radar stations and lookout posts was responsible for detecting incoming raids. Due to shortages of radar and other fire control equipment, Japanese antiaircraft gunners found it difficult to target aircraft operating at night. The radar stations had a short range and fire control equipment for the antiaircraft batteries was unsophisticated. As of March 1945, most of the 10th Air Division's 210 combat aircraft were day fighters, with the 53rd Air Regiment operating 25 or 26 night fighters. The regiment was experiencing difficulties converting to the night fighter role, which included an overly intensive training program that exhausted its pilots.

Tokyo's civil defenses were also lacking. The city's fire department comprised around 8,000 firemen spread between 287 fire stations, but they had little modern firefighting equipment. The firefighting tactics used by the fire department were ineffective against incendiary bombs. Civilians had been organized into more than 140,000 neighborhood firefighting associations with a nominal strength of 2.75 million people, but these were also ill-equipped. The basic equipment issued to the firefighting associations was incapable of extinguishing fires started by M69s. Few air raid shelters had been constructed, though most households dug crude foxholes to shelter in near their homes. Firebreaks had been created across the city in an attempt to stop the spread of fire; over 200,000 houses were destroyed as part of this effort. Rubble was often not cleared from the firebreaks, which provided a source of fuel. The Japanese Government also encouraged children and civilians with non-essential jobs to evacuate Tokyo, and 1.7 million had departed by March 1945. However, many other civilians had moved into Tokyo from impoverished rural areas over the same period.

Attack

Departure

On 8 March, LeMay issued orders for a major firebombing attack on Tokyo the next night. The raid was to target a rectangular area in northeastern Tokyo designated Zone I by the USAAF which measured approximately by . This area was divided by the Sumida River, and included most of Asakusa, Honjo and Fukagawa Wards. These wards formed part of the informally defined Shitamachi district of Tokyo, which was mainly populated by working-class people and artisans. With a population of around 1.1 million, it was one of the most densely populated urban areas in the world. Zone I contained few militarily significant industrial facilities, though there were a large number of small factories which supplied Japan's war industries. The area was highly vulnerable to firebombing, as most buildings were constructed from wood and bamboo and were closely spaced. Due to this vulnerability, it had suffered extensive damage and heavy casualties from fires caused by the 1923 Great Kantō earthquake. The United States' intelligence services were aware of how vulnerable the region remained to fire, with the Office of Strategic Services rating it as containing the most combustible districts in Tokyo.

The orders for the raid issued to the B-29 crews stated that the main purpose of the attack was to destroy the many small factories located within the target area, but also noted that it was intended to cause civilian casualties as a means of disrupting production at major industrial facilities. Each of XXI Bomber Command's three wings was allocated a different altitude to bomb from, in bands between and . These altitudes were calculated to be too high for the light Japanese antiaircraft guns to reach, and below the effective range of the heavy antiaircraft guns.

LeMay was unable to lead the raid in person as he had been prohibited from placing himself in a situation where he could be captured after being briefed on the development of atomic bombs. Instead, the attack was led by the 314th Bombardment Wing's commanding officer, Brigadier General Thomas S. Power. LeMay considered Power to be the best of the wing commanding officers. The new tactics which were to be used in the operation were not well received by many airmen, who believed that it was safer to bomb from high altitudes and preferred to retain their defensive guns. Leaving behind the unneeded gunners also troubled many of the airmen, as bomber crews typically had a very close relationship.

In preparation for the attack, XXI Bomber Command's maintenance staff worked intensively over a 36-hour period to ready as many aircraft as possible. This effort proved successful, and 83 percent of the B-29s were available for action compared to the average serviceability rate of 60 percent. Other ground crew loaded the aircraft with bombs and fuel. A total of 346 B-29s were readied. The 73rd Bombardment Wing contributed 169 B-29s and the 313th Bombardment Wing 121; both units were based on Saipan. At the time of the raid the 314th Bombardment Wing was arriving at Guam in the Marianas, and able to provide only 56 B-29s. The B-29s in the squadrons which were scheduled to arrive over Tokyo first were armed with M47 bomb was encountered on the flight to Japan, but the weather over Tokyo was good. There was little cloud cover, and visibility was good for the first bomber crews to arrive over Tokyo; they were able to see clearly for . Conditions on the ground were cold and windy, with the city experiencing gusts of between and blowing from the southeast.

The first B-29s over Tokyo were four aircraft tasked with guiding the others in. These Superfortresses arrived over the city shortly before midnight on 9March. They carried extra fuel, additional radios and XXI Bomber Command's best radio operators instead of bombs, and circled Tokyo at an altitude of throughout the raid. This tactic proved unsuccessful, and was later judged to have been unnecessary.

Over Tokyo

The attack on Tokyo commenced at 12:08 am local time on 10 March. Pathfinder bombers simultaneously approached the target area at right angles to each other. These bombers were manned by the 73rd and 313th Bombardment Wings' best crews. Their M47 bombs rapidly started fires in an ''X'' shape, which was used to direct the attacks for the remainder of the force. Each of XXI Bomber Command's wings and their subordinate groups had been briefed to attack different areas within the ''X'' shape to ensure that the raid caused widespread damage. As the fires expanded, the American bombers spread out to attack unaffected parts of the target area. Power's B-29 circled Tokyo for 90 minutes, with a team of cartographers who were assigned to him mapping the spread of the fires.

The raid lasted for approximately two hours and forty minutes. Visibility over Tokyo decreased over the course of the raid due to the extensive smoke over the city. This led some American aircraft to bomb parts of Tokyo well outside the target area. The heat from the fires also resulted in the final waves of aircraft experiencing heavy turbulence. Some American airmen also needed to use oxygen masks when the odor of burning flesh entered their aircraft. A total of 279 B-29s attacked Tokyo, dropping of bombs. Another 19 Superfortresses which were unable to reach Tokyo struck targets of opportunity or targets of last resort. These aircraft turned back early due to mechanical problems or pilots deciding to abort the main mission because they were afraid of being killed.

Tokyo's defenders were expecting an attack, but did not detect the American force until it arrived over the city. The air defense units in the Kanto Plain area had been placed on alert, but the night fighter units were instructed not to sortie any aircraft until an incoming raid was detected. While picket boats spotted the attack force, poor radio reception meant that most of their reports were not received. Due to disorganization in the defense commands, little action was taken on the scattered reports which came in from the boats. At around midnight on 9March a small number of B-29s were detected near Katsuura, but were thought to be conducting reconnaissance flights. Subsequent sightings of B-29s flying at low levels were not taken seriously, and the Japanese radar stations focused on searching for American aircraft operating at their usual high altitudes. The first alarm that a raid was in progress was issued at 12:15 am, just after the B-29s began dropping bombs on Tokyo. The 10th Air Division sortied all of its available night interceptors, and the 1st Anti aircraft Division's searchlight and anti aircraft units went into action.

As expected by LeMay, the defense of Tokyo was not effective. Many American units encountered considerable anti aircraft fire, but it was generally aimed at altitudes either above or below the bombers and reduced in intensity over time as gun positions were overwhelmed by fires. Nevertheless, the Japanese gunners shot down 12 B-29s. A further 42 were damaged, of which two had to be written off. The Japanese fighters were ineffective; their pilots received no guidance from radar stations and the efforts of the anti aircraft gunners and fighter units were not coordinated. No B-29s were shot down by fighters, and the American airmen reported only 76 sightings of Japanese fighters and 40 attacks by them over the course of the raid. Several Japanese pilots were killed when their aircraft ran out of fuel and crashed. Five of the downed B-29s managed to ditch in the sea, and their crews were rescued by United States Navy submarines. American casualties were 96 airmen killed or missing, and 6wounded or injured.

The surviving B-29s arrived back at their bases in the Mariana Islands between 6:10 and 11:27 am local time on 10 March. Many of the bombers were streaked with ashes from the fires their crews had caused.

On the ground

Widespread fires rapidly developed across northeastern Tokyo. Within 30 minutes of the start of the raid the situation was beyond the fire department's control. An hour into the raid the fire department abandoned its efforts to stop the conflagration. Instead, the firemen focused on guiding people to safety and rescuing those trapped in burning buildings. Over 125 firemen and 500 civil guards who had been assigned to help them were killed, and 96 fire engines destroyed.

Driven by the strong wind, the large numbers of small fires started by the American incendiaries rapidly merged into major blazes. These formed firestorms which quickly advanced in a northwesterly direction and destroyed or damaged almost all the buildings in their path. The only buildings which survived the fire were constructed of stone. By an hour after the start of the attack most of eastern Tokyo either had been destroyed or was being affected by fires.

Civilians who stayed at their homes or attempted to fight the fire had virtually no chance of survival. Historian Richard B. Frank

HOME


Content is Copyleft
Website design, code, and AI is Copyrighted (c) 2014-2017 by Stephen Payne


Consider donating to Wikimedia



As an Amazon Associate I earn from qualifying purchases