World War II Day by Day

509th Composite Group HQ, Tinian, Mariana Islands • August 6, 1945

For several months the U.S. had dropped more than 63 mil­lion leaf­lets across Japan, warning civil­ians of devas­tating aerial bombings and to evacu­ate the cities identi­fied in the leaf­lets. Radio broad­casts from the Amer­ican-held island of Saipan under­scored the printed warnings. Many Japa­nese cities suffered ter­rible damage from napalm bombs that set their wood-frame buildings on fire. On August 1, 1945, in the largest bomb raid suffered by Japa­nese cities, 80 per­cent of Hachioji, a rail choke point near Tokyo, was burned out by napalm; 65 per­cent of Naga­oka was wasted the same day. Nearly 100 per­cent of Toyama, an alu­mi­num-pro­ducing city, was incin­erated. On August 5 four more Japa­nese cities were turned into smoking ruins. The areas destroyed and the number of people killed in U.S. air raids on Japan up till then exceeded the areas destroyed and the lives lost in all German cities by the U.S. and Royal air forces combined between May 15, 1940, and the end of the war in Europe five years later.

On this date, August 6, 1945, things were different. Seventy-eight years ago today, Hiro­shima, a city of 280,000 civil­ians and 43,000 sol­diers on the Japanese main­land of Honshū, was incin­er­ated by a 5‑ton ura­nium-filled bomb code­named “Little Boy,” the first of two atomic bombs ever dropped on an enemy nation. A blinding flash lasting per­haps a tenth of a second created an ear­split­ting explo­sion that blew out win­dows 6½ miles from the epi­center—Hiro­shima’s city center—and sent a mas­sive column of debris and smoke miles high.

Allied forces were poised for invasion hun­dreds of miles from the Japa­nese Home Islands when the first atomic bomb exploded. Remem­brance of the horri­fic casu­al­ties in­flicted by a fanat­i­cal enemy on Amer­i­cans assaulting Japan’s off­shore islands of Iwo Jima and Oki­nawa (Febru­ary 19 to June 22, 1945)—nearly 70,000 dead and wounded—fore­bode worse num­bers ahead, as high as one mil­lion Allied service­men and mil­lions more Japa­nese. (Actually, the U.S. Joint Chiefs of Staff esti­mated likely Amer­i­can casu­al­ties of 31,000 during the first month of Operat­ion Olym­pic, the inva­sion of the southern island of Kyūshū; the one million figure was ginned up after the war.) Presi­dent Harry S. Truman and Amer­i­can com­manders fretted that a war-weary public might have neither the patience nor the stomach for a Japanese-style Armageddon on Japan’s home turf.

After the Hiro­shima bombing, the White House issued a state­ment that pro­mised Japan “a rain of ruin from the air, the like of which has never been seen on earth” if the country’s mili­tary leader­ship did not end the war in 48 hours on U.S. terms. To a group of Chris­tian leaders Truman explained his motives for deploying the atomic bomb: “When you have to deal with a beast you have to treat him as a beast.” (The Presi­dent shared the view held by most white Amer­i­cans that the Japa­nese were not quite human.) Con­sid­ering the reli­gious char­ac­ter of those he addressed at the time, Truman expressed no moral qualms about snuffing out tens of thou­sands of inno­cent lives along with the lives of the guilty—the military die-hards who refused to admit defeat.

Japanese leaders had expected, indeed planned for a bru­tal, no-holds-barred land inva­sion begin­ning in October. But nothing in their past experi­ence or in their wildest imag­i­na­tions had pre­pared them for this level of aerial immo­la­tion on that warm August morning. The deadly new weapon system was the equi­va­lent of 220 fully loaded B‑29 heavy bombers dropping their loads in an instant. Within minutes of the bomb’s brill­iant flash and ear­split­ting crack 40,000 Hiro­shima men, women, and chil­dren died mostly in the fire­storms set off by the enor­mous blast. People within a third of a mile (500 meters) of ground zero (hypo­center) were instantly incin­er­ated. Hun­dreds, maybe thou­sands simply suffo­cated, as the explo­sion con­sumed oxygen in the blast area, leaving little of the ele­ment left for people to breathe. A further 90,000–166,000 victims would die of burns and radia­tion within days or weeks. Survivors of the blast, hiba­kusha (lit. “explosion-affected people”), lived out their lives with the fear of con­tracting radia­tion-related dis­orders (many suc­cumbed years later to leu­kemia or other cancers) or passing malignant genetic diseases onto their children.

Hiroshima Atomic Bomb: Delivering a Foretaste of National Apocalypse

Left: Ground level photograph of the Hiro­shima radio­active mush­room cloud taken from approx­i­mately 4.3 miles north­east of ground zero, the com­mer­cial center and resi­den­tial area of the city. “Little Boy,” as the ura­nium‑235 bomb was nick­named, deto­nated 1,900 ft above the Shima Hos­pital and 550 yards from the bombar­dier’s aiming point, the Aioi Bridge. Three days later another mush­room cloud appeared over the city of Naga­saki, the pro­duct of “Fat Man,” as the pluto­nium‑239 bomb was called. Less than a minute after falling earth­ward, the bombs trans­formed both cities into rubble. (They also trans­formed the world, though very differently.) The following day Japan capitulated.

Right: Lost image found in Honkawa Elementary School in 2013 of the Hiro­shima radio­active mush­room cloud, believed to have been taken 20–30 minutes after deto­na­tion from about 6.2 miles east of ground zero. Some 400 Hon­kawa students and more than 10 teachers were victims of the bomb blast. Survi­vors of Hiro­shima and Naga­saki often use the term pika-don, which transl­ates as “flash-bang” or “flash-boom,” to describe how the atomic wea­pons pro­duced a blinding light before the explo­sion. They find their term suc­cinctly cap­tures the dazzling sight and thundering sound they experienced up close.

Left: The best-known photographs of the bomb’s after­math were taken from the air by one of three Boeing B‑29s that left Tinian in the Mari­ana Islands in the pre­dawn hours of August 6, 1945, for Hiro­shima. This aerial photo­graph is less well known, taken about one hour after the atomic bomb deto­nated over Hiro­shima, a city the size of Houston, Texas. “Little Boy” was carried by the Enola Gay, a modi­fied B‑29 Super­for­tress (a so-called “Silver­plate” Super­for­tress con­figured to carry an atomic bomb) that was piloted by 30‑year-old Col. Paul Tibbets, Jr. Tibbets had devel­oped his flying skills as a pilot for the U.S. Eighth and Twelfth Air Forces over Europe and North Africa. In March 1943 Tibbets returned to the States to test-fly the new Super­fortress, earning him the nick­name “Mr. B‑29.” Inter­est­ingly, it was Brig. Gen. Leslie Groves, mili­tary head of the Man­hat­tan Pro­ject, who settled on Tibbets and the Boeing heavy bomber to deliver the coup de grâce to World War II.

Right: Nearly 11 feet long and 5 inches in dia­meter, “Little Boy” lies on trailer cradle before being loaded into Enola Gay’s bomb bay. The plane’s bomb bay door is visible in the upper right-hand corner of the photo. Of the 131 lb of ura­nium‑235 in the bomb, less than 2 lb under­went nuclear fis­sion. The force of the explo­sion was roughly equiv­a­lent to 15,000 tons (15 kilo­tons) of TNT. (The common size today is several hundred kilo­tons.) Almost all of the energy was released in the ini­tial 30 seconds after deto­na­tion: 50 per­cent in a pres­sure shock wave, 35 per­cent in the form of light and heat (the sur­face tem­per­a­ture of the fire­ball was 10,800°F, or 6,000°C, which approx­i­mates the tem­per­a­ture of the sun’s sur­face), and 5 perc­ent in nuclear radi­a­tion. The flash of light from the blast could have been seen on a neighboring planet.

Left: The Hiroshima Chamber of Industry and Com­merce Building was the only building remotely close to standing near the epi­center of the atomic bomb blast of August 6, 1945. Known today as the Gen­baku (“Atom Bomb” in Japa­nese) Dome, it was left unre­paired as a reminder of the event. On Decem­ber 7, 1996, the iconic Gen­baku Dome was added to the UNESCO World Heri­tage List. It sits in a lush park, the Hiro­shima Peace Memo­rial Park, sur­rounded by a city of one million people. For many visitors the memo­rial park and museum are hallowed ground, like a ceme­tery, because the ashes and bones of the bombing vic­tims are literally under­foot in a thin white layer a few feet beneath the earth’s surface. A Chil­dren’s Peace Monu­ment in the park was unveiled on Chil­dren’s Day, May 5, 1958, to com­mem­o­rate the thou­sands of inno­cent young vic­tims, but in partic­ular of Sadako Sasak who at age 12 died of radi­a­tion-induced leu­ke­mia 10 years after “Little Boy” was dropped on Hiroshima.

Right: Eight months after America’s ultimate weapon was dropped, Hiro­shima still stands in ruins, the visible evi­dence of the world’s first use of nuclear weapons in war. Of the 68 cities bombed in the sum­mer of 1945, Hiro­shima was fourth in terms of square miles destroyed, 17th in the percent­age of the city destroyed, but second in the number of civilian deaths.

Well-Done Documentary on the Atomic Bombing of Hiroshima and Nagasaki, August 6 and 9, 1945