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; sixty-five 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. Hiro­shima, a city of 280,000 civil­ians and 43,000 sol­diers on the Japanese main­land of Honshū, was incin­er­ated by a five-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 6‑1/2 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.” ­Con­sid­ering the char­ac­ter of those he addressed, 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‑29s 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”), often succumbed years later to leukemia or other cancers.

Hiroshima A-Bomb: Delivering a Foretaste of National Apocalypse

Hiroshima A-bomb mushroom cloud taken 4.3 miles northeast of ground zero Hiroshima A-bomb mushroom cloud taken 6.2 miles east of ground zero

Left: Ground level photograph of the Hiro­shima mush­room cloud taken from approx­i­mately 4.3 miles north­east of ground zero. “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. The following day Japan capit­u­lated, dispatching a letter of pro­test to the U.S. govern­ment via the Swiss embassy over the two atomic bombings­.

Right: Lost image found in Honkawa Elementary School in 2013 of the Hiro­shima 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.

Hiroshima A-bomb mushroom cloud taken 50 miles away Hiroshima A-bomb: Little Boy prior to loading

Left: The best-known photographs of the bomb’s after­math were taken from the air by one of three 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. “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.”

Right: “Little Boy” on trailer cradle before being loaded into Enola Gay’s bomb bay. The Enola Gay’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 of TNT. 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), and 5 percent in nuclear radiation.

Hiroshima Chamber of Industry and Commerce Building Hiroshima, March 1946

Left: The Hiroshima Chamber of Industry and Commerce Building (aka Hiro­shima Prefec­tural Indus­trial Pro­mo­tion Hall) was the only building remotely close to standing near the center of the atomic bomb blast of August 6, 1945. Known today as the A-Bomb Dome, it was left unrepaired as a reminder of the event and now sits in a lush park known as the Hiroshima Peace Memorial Park.

Right: Eight months after the atomic bomb 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