Atomic Bombings on Hiroshima and Nagasaki Part IV

 Bombing of Nagasaki

Responsibility for the timing of the second bombing was delegated to Tibbets. Scheduled for 11 August, the raid was moved earlier by two days to avoid a five-day period of bad weather forecast to begin on 10 August. Three bomb pre-assemblies had been transported to Tinian, labeled F-31, F-32, and F-33 on their exteriors. On 8 August, a dress rehearsal was conducted off Tinian by Sweeney using Bockscar as the drop airplane. Assembly F-33 was expended testing the components and F-31 was designated for the 9 August mission.

At 03:47 Tinian time (GMT+10), 02:47 Japanese time, on the morning of 9 August 1945, Bockscar, flown by Sweeney's crew, lifted off from Tinian island with the Fat Man, with Kokura as the primary target and Nagasaki the secondary target. The mission plan for the second attack was nearly identical to that of the Hiroshima mission, with two B-29s flying an hour ahead as weather scouts and two additional B-29s in Sweeney's flight for instrumentation and photographic support of the mission. Sweeney took off with his weapon already armed but with the electrical safety plugs still engaged.

During pre-flight inspection of Bockscar, the flight engineer notified Sweeney that an inoperative fuel transfer pump made it impossible to use 2,400 liters (640 U.S. gal) of fuel carried in a reserve tank. This fuel would still have to be carried all the way to Japan and back, consuming still more fuel. Replacing the pump would take hours; moving the Fat Man to another aircraft might take just as long and was dangerous as well, as the bomb was live. Tibbets and Sweeney therefore elected to have Bockscar continue the mission.

This time Penney and Cheshire were allowed to accompany the mission, flying as observers on the third plane, Big Stink, flown by the group's operations officer, Major James I. Hopkins, Jr. Observers aboard the weather planes reported both targets clear. When Sweeney's aircraft arrived at the assembly point for his flight off the coast of Japan, Big Stink failed to make the rendezvous. According to Cheshire, Hopkins was at varying heights including 2,700 meters (9,000 ft) higher than he should have been, and was not flying tight circles over Yakushima as previously agreed with Sweeney and Captain Frederick C. Bock, who was piloting the support B-29 The Great Artiste. Instead, Hopkins was flying 64-kilometer (40 mi) dogleg patterns. Though ordered not to circle longer than fifteen minutes, Sweeney continued to wait for Big Stink for forty minutes. Before leaving the rendezvous point, Sweeney consulted Ashworth, who was in charge of the bomb. As commander of the aircraft, Sweeney made the decision to proceed to the primary, the city of Kokura.

After exceeding the original departure time limit by nearly a half-hour, Bockscar, accompanied by The Great Artiste, proceeded to Kokura, thirty minutes away. The delay at the rendezvous had resulted in clouds and drifting smoke over Kokura from fires started by a major firebombing raid by 224 B-29s on nearby Yahata the previous day. Additionally, the Yahata Steel Works intentionally burned coal tar, to produce black smoke. The clouds and smoke resulted in 70 percent of the area over Kokura being covered, obscuring the aiming point. Three bomb runs were made over the next 50 minutes, burning fuel and exposing the aircraft repeatedly to the heavy defenses around Kokura, but the bombardier was unable to drop visually. By the time of the third bomb run, Japanese anti-aircraft fire was getting close, and Second Lieutenant Jacob Beser, who was monitoring Japanese communications, reported activity on the Japanese fighter direction radio bands.

With fuel running low because of the failed fuel pump, Bockscar and The Great Artiste headed for their secondary target, Nagasaki. Fuel consumption calculations made en route indicated that Bockscar had insufficient fuel to reach Iwo Jima and would be forced to divert to Okinawa, which had become entirely Allied-occupied territory only six weeks earlier. After initially deciding that if Nagasaki were obscured on their arrival the crew would carry the bomb to Okinawa and dispose of it in the ocean if necessary, Ashworth agreed with Sweeney's suggestion that a radar approach would be used if the target was obscured. At about 07:50 Japanese time, an air raid alert was sounded in Nagasaki, but the "all clear" signal was given at 08:30. When only two B-29 Superfortresses were sighted at 10:53 Japanese Time (GMT+9), the Japanese apparently assumed that the planes were only on reconnaissance and no further alarm was given.

A few minutes later at 11:00 Japanese Time, The Great Artiste dropped instruments attached to three parachutes. These instruments also contained an unsigned letter to Professor Ryokichi Sagane, a physicist at the University of Tokyo who studied with three of the scientists responsible for the atomic bomb at the University of California, Berkeley, urging him to tell the public about the danger involved with these weapons of mass destruction. The messages were found by military authorities but not turned over to Sagane until a month later. In 1949, one of the authors of the letter, Luis Alvarez, met with Sagane and signed the letter.

At 11:01 Japanese Time, a last-minute break in the clouds over Nagasaki allowed Bockscar's bombardier, Captain Kermit Beahan, to visually sight the target as ordered. The Fat Man weapon, containing a core of about 5 kg (11 lb) of plutonium, was dropped over the city's industrial valley. It exploded 47 seconds later at 11:02 Japanese Time at 503 ± 10 m (1,650 ± 33 ft), above a tennis court, halfway between the Mitsubishi Steel and Arms Works in the south and the Nagasaki Arsenal in the north. This was nearly 3 km (1.9 mi) northwest of the planned hypocenter; the blast was confined to the Urakami Valley and a major portion of the city was protected by the intervening hills.[208] The resulting explosion released the equivalent energy of 21 ± 2 kt (87.9 ± 8.4 TJ). Big Stink spotted the explosion from 160 kilometers (100 mi) away, and flew over to observe.

Bockscar flew on to Okinawa, arriving with only sufficient fuel for a single approach. Sweeney tried repeatedly to contact the control tower for landing clearance, but received no answer. He could see heavy air traffic landing and taking off from Yontan Airfield. Firing off every flare on board to alert the field to his emergency landing, the Bockscar came in fast, landing at 230 km/h (140 mph) instead of the normal 190 kilometers per hour (120 mph). The number two engine died from fuel starvation as he began the final approach. Touching down on only three engines midway down the landing strip, Bockscar bounced up into the air again for about 7.6 meters (25 ft) before slamming back down hard. The heavy B-29 slewed left and towards a row of parked B-24 bombers before the pilots managed to regain control. Its reversible propellers were insufficient to slow the aircraft adequately, and with both pilots standing on the brakes, Bockscar made a swerving 90-degree turn at the end of the runway to avoid running off it. A second engine died from fuel exhaustion before the plane came to a stop.

Following the mission, there was confusion over the identification of the plane. The first eyewitness account by war correspondent William L. Laurence of The New York Times, who accompanied the mission aboard the aircraft piloted by Bock, reported that Sweeney was leading the mission in The Great Artiste. He also noted its "Victor" number as 77, which was that of Bockscar. Laurence had interviewed Sweeney and his crew, and was aware that they referred to their airplane as The Great Artiste. Except for Enola Gay, none of the 393d's B-29s had yet had names painted on the noses, a fact which Laurence himself noted in his account. Unaware of the switch in aircraft, Laurence assumed Victor 77 was The Great Artiste, which was in fact, Victor 89.

Events on the ground

Although the bomb was more powerful than the one used on Hiroshima, its effects were confined by hillsides to the narrow Urakami Valley. Of 7,500 Japanese employees who worked inside the Mitsubishi Munitions plant, including "mobilized" students and regular workers, 6,200 were killed. Some 17,000–22,000 others who worked in other war plants and factories in the city died as well. The 1946 Manhattan Project report estimated 39,000 dead and 25,000 injured, and the 1951 U.S.-led Joint Commission report estimated 39,214 dead and 25,153 injured; Japanese-led reconsiderations in the 1970s estimated 70,000 dead in Nagasaki by the end of the year. A modern estimate by the Radiation Effects Research Foundation (RERF) estimates a city population of 250,000 to 270,000 at the time of the bombing, of which 60,000 to 80,000 died by the end of the year.

Unlike Hiroshima's military death toll, only 150 Japanese soldiers were killed instantly, including 36 from the 134th AAA Regiment of the 4th AAA Division. At least eight Allied prisoners of war (POWs) died from the bombing, and as many as thirteen may have died. The eight confirmed deaths included a British POW, Royal Air Force Corporal Ronald Shaw, and seven Dutch POWs. One American POW, Joe Kieyoomia, was in Nagasaki at the time of the bombing but survived, reportedly having been shielded from the effects of the bomb by the concrete walls of his cell. There were 24 Australian POWs in Nagasaki, all of whom survived.

The radius of total destruction was about 1.6 km (1 mi), followed by fires across the northern portion of the city to 3.2 km (2 mi) south of the bomb. About 58 percent of the Mitsubishi Arms Plant was damaged, and about 78 percent of the Mitsubishi Steel Works. The Mitsubishi Electric Works suffered only 10 percent structural damage as it was on the border of the main destruction zone. The Nagasaki Arsenal was destroyed in the blast. Although many fires likewise burnt following the bombing, in contrast to Hiroshima where sufficient fuel density was available, no firestorm developed in Nagasaki as the damaged areas did not furnish enough fuel to generate the phenomenon. Instead, ambient wind pushed the fire spread along the valley. Had the bomb been dropped more precisely at the intended aiming point, which was downtown Nagasaki at the heart of the historic district, the destruction to medical and administrative infrastructure would have been even greater.

As in Hiroshima, the bombing badly dislocated the city's medical facilities. A makeshift hospital was established at the Shinkozen Primary School, which served as the main medical center. The trains were still running, and evacuated many victims to hospitals in nearby towns. A medical team from a naval hospital reached the city in the evening, and fire-fighting brigades from the neighboring towns assisted in fighting the fires. Takashi Nagai was a doctor working in the radiology department of Nagasaki Medical College Hospital. He received a serious injury that severed his right temporal artery, but joined the rest of the surviving medical staff in treating bombing victims.

The atomic bomb explosion generated a windstorm several kilometers wide that carried ash, dust, and debris over the mountain ranges surrounding Nagasaki. Approximately 20 minutes after the bombing, a black rain with the consistency of mud or oil came down carrying radioactive material for one to two hours before turning clear.

Plans for more atomic attacks on Japan

There were plans for further attacks on Japan following Hiroshima and Nagasaki. Groves expected to have another "Fat Man" atomic bomb ready for use on 19 August, with three more in September and a further three in October. A second Little Boy bomb (using U-235) would not be available until December 1945. On 10 August, he sent a memorandum to Marshall in which he wrote that "the next bomb ... should be ready for delivery on the first suitable weather after August 17 or 18." The memo today contains hand-written comment written by Marshall: "It is not to be released over Japan without express authority from the President."

At the cabinet meeting that morning, Truman discussed these actions. James Forrestal paraphrased Truman as saying "there will be further dropping of the atomic bomb," while Henry A. Wallace recorded in his diary that: "Truman said he had given orders to stop atomic bombing. He said the thought of wiping out another 100,000 people was too horrific. He didn't like the idea of killing, as he said, 'all those kids.'" The previous order that the target cities were to be attacked with atomic bombs "as made ready" was thus modified. There was already discussion in the War Department about conserving the bombs then in production for Operation Downfall, and Marshall suggested to Stimson that the remaining cities on the target list be spared attack with atomic bombs.

Two more Fat Man assemblies were readied, and scheduled to leave Kirtland Field for Tinian on 11 and 14 August, and Tibbets was ordered by LeMay to return to Albuquerque, New Mexico, to collect them. At Los Alamos, technicians worked 24 hours straight to cast another plutonium core. Although cast, it still needed to be pressed and coated, which would take until 16 August. Therefore, it could have been ready for use on 19 August. Unable to reach Marshall, Groves ordered on his own authority on 13 August that the core should not be shipped.

Surrender of Japan and subsequent occupation

Until 9 August, Japan's war council still insisted on its four conditions for surrender. The full cabinet met at 14:30 on 9 August, and spent most of the day debating surrender. Anami conceded that victory was unlikely, but argued in favor of continuing the war. The meeting ended at 17:30, with no decision having been reached. Suzuki went to the palace to report on the outcome of the meeting, where he met with Kōichi Kido, the Lord Keeper of the Privy Seal of Japan. Kido informed him that the emperor had agreed to hold an imperial conference, and gave a strong indication that the emperor would consent to surrender on condition that kokutai be preserved. A second cabinet meeting was held at 18:00. Only four ministers supported Anami's position of adhering to the four conditions, but since cabinet decisions had to be unanimous, no decision was reached before it ended at 22:00.

Calling an imperial conference required the signatures of the prime minister and the two service chiefs, but the Chief Cabinet Secretary Hisatsune Sakomizu had already obtained signatures from Toyoda and General Yoshijirō Umezu in advance, and he reneged on his promise to inform them if a meeting was to be held. The meeting commenced at 23:50. No consensus had emerged by 02:00 on 10 August, but the emperor gave his "sacred decision", authorizing the Foreign Minister, Shigenori Tōgō, to notify the Allies that Japan would accept their terms on one condition, that the declaration "does not comprise any demand which prejudices the prerogatives of His Majesty as a Sovereign ruler."

On 12 August, the Emperor informed the imperial family of his decision to surrender. One of his uncles, Prince Asaka, asked whether the war would be continued if the kokutai could not be preserved. Hirohito simply replied, "Of course." As the Allied terms seemed to leave intact the principle of the preservation of the Throne, Hirohito recorded on 14 August his capitulation announcement which was broadcast to the Japanese nation the next day despite an attempted military coup d'état by militarists opposed to the surrender.

In his declaration's fifth paragraph, Hirohito solely mentions the duration of the conflict; and did not explicitly mention the Soviets as a factor for surrender:

But now the war has lasted for nearly four years. Despite the best that has been done by every one—the gallant fighting of military and naval forces, the diligence and assiduity of Our servants of the State and the devoted service of Our one hundred million people, the war situation has developed not necessarily to Japan's advantage, while the general trends of the world have all turned against her interest.

The sixth paragraph by Hirohito specifically mentions the use of nuclear ordnance devices, from the aspect of the unprecedented damage they caused:

Moreover, the enemy has begun to employ a new and most cruel bomb, the power of which to do damage is, indeed, incalculable, taking the toll of many innocent lives. Should we continue to fight, not only would it result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization.

The seventh paragraph gives the reason for the ending of hostilities against the Allies:

Such being the case, how are we to save the millions of our subjects, or to atone ourselves before the hallowed spirits of our imperial ancestors? This is the reason why we have ordered the acceptance of the provisions of the joint declaration of the powers.

In his "Rescript to the Soldiers and Sailors" delivered on 17 August, Hirohito did not refer to the atomic bombs or possible human extinction, and instead described the Soviet declaration of war as "endangering the very foundation of the Empire's existence."