On Monday, August 6, 1945, a mushroom cloud billows into the sky about one hour after an atomic bomb was dropped by American B-29 bomber, the Enola Gay, detonating above Hiroshima, Japan. Nearly 80,000 people are believed to have been killed immediately, with possibly another 60,000 survivors dying of injuries and radiation exposure by 1950. #

This aerial photograph made on day five of the invasion shows the immense power needed to break the back of Japanese Resistance on Iwo Jima, on March 17, 1945. Just off the beach, landing craft await their chance at the unloading area while small boats from the transports ply back and forth bring assault troops and returning wounded for treatment. Further out, the transports themselves faintly along the horizon, the protective screen of destroyers, destroyer escorts and cruisers can be seen. On the island, Marine tanks can be spotted moving through the rough terrain toward the first airfield at left. #

Anti-aircraft gunners, center foreground, pour a deadly stream of fire into an already-burning Japanese Kamikaze plane plummeting toward the flight deck of the USS Sangamon, a Navy escort carrier, during action in the Ryukyu Islands near Japan, on May 4, 1945. This suicide plane landed in the sea close to the carrier. Another Japanese aircraft later succeeded in hitting the ship deck, inflicting heavy damage. #

Flames leap from the deck of the USS Bunker Hill, after it was hit by two Kamikazes in 30 seconds on May 11, 1945 off Kyushu. 346 aboard were killed, another 264 wounded. #

Perched on the rim of a gaping hole in the wall of a theater in the Ryukyu capital, a Marine rifleman views the result of the American bombardment of Naha, Okinawa, Japan, on June 13, 1945. Structure skeletons are all that remain of the city with a pre-invasion population of 443,000 people. #

A night view of burning Toyama, Japan on August 1, 1945, after 173 American B-29 bombers dropped incendiary bombs on the city. Formerly a big producer of aluminum, the city was 95.6% demolished. #

After an incendiary bombing, a view of some of the damage in Tokyo, Japan in 1945. A strip of residential buildings remains undamaged, surrounded by ashes and rubble of neighboring structures burned or blasted to the ground. #

In July of 1945, the United States was in the final stages of developing a powerful and deadly new weapon - the Atomic Bomb. Here, Los Alamos director J. Robert Oppenheimer is seen in silhouette as he oversees final assembly of "The Gadget", the first nuclear device to be detonated, at the Trinity test site in New Mexico. #

Incendiary bombs are dropped from B-29 Superfortresses of the U.S. Army Air Forces on already-burning landing piers and surrounding buildings in Kobe, Japan, on June 4, 1945. #

The terrible damage done to Tokyo by American bombers can be seen in what was once a residential district in the Japanese capital, viewed months later, on September 10, 1945. Only large well constructed buildings remain intact. #

Following the July 26 Potsdam Declaration, where Allies outlined the terms of surrender for Japan and promised "inevitable and complete destruction" of Japan if they failed to comply, preparations were secretly under way to make use of the newly-tested Atomic Bomb. Here, the first nuclear device to be used as a weapon, codenamed "Little Boy", rests on trailer cradle in a pit, ready for loading into the bomb bay of the "Enola Gay" in August of 1945. #

The U.S. B-29 Superfortress bomber "Enola Gay" took off from Tinian Island very early on the morning of August 6th, carrying "Little Boy", a 4,000 kg (8,900 lb) uranium bomb. At 8:15 am, Little Boy was dropped from 9,400 m (31,000 ft) above the city, freefalling for 57 seconds while a complicated series of fuse triggers looked for a target height of 600 m (2,000 ft) above the ground. At the moment of detonation, a small explosive initiated a super-critical mass in 64 kg (141 lbs) of uranium. Of that 64 kg, only .7 kg (1.5 lbs) underwent fission, and of that mass, only 600 milligrams was converted into energy - an explosive energy that seared everything within a few miles, flattened the city below with a massive shockwave, set off a raging firestorm and bathed every living thing in deadly radiation. At the time this photo was made, smoke billowed in a column 20,000 feet above Hiroshima while smoke from the burst had spread over 10,000 feet at the base of the rising column. #

A pall of smoke lingers over this scene of destruction in Hiroshima, Japan, on August 7, 1945, a day after the explosion of the atomic bomb. Nearly 80,000 people are believed to have been killed immediately, with possibly another 60,000 survivors dying of injuries and radiation exposure by 1950. #

The searing heat from the nuclear explosion above Hiroshima scorched the roadway of this bridge across the Ota River, about a half a mile from the focal point of the bomb burst. The areas shielded by the concrete pillars and railings were left undamaged, creating permanent "shadows" on the bridge deck. #

Only days after the bombing of Hiroshima, the second operational nuclear weapon was readied by the U.S. Called "Fat Man", the unit is seen being placed on a trailer cradle in August of 1945. When the Japanese still refused to surrender after Hiroshima, U.S. President Truman issued a statement saying in part "If they do not now accept our terms, they may expect a rain of ruin from the air, the like of which has never been seen on this earth." #

"Fat Man" was dropped from the B-29 bomber Bockscar, detonating at 11:02 AM, at an altitude of about 1,650 feet (500 m) above Nagasaki. An estimated 39,000 people were killed outright by the bombing a further 25,000 were injured. #

This picture made shortly after the August 9, 1945 atomic bombing, shows workers carrying away debris in a devastated area of Nagasaki, Japan. This picture obtained by the U.S. Army from files of Domei, the official Japanese news agency, was the first ground view of the nuclear destruction in Nagasaki. #

Dr. Nagai, medical instructor and x-ray specialist at Nagasaki Hospital, a victim of atomic radiation caused by the nuclear bombing. A few days after this photo was made, Dr. Nagai passed away. #

People walk through the charred ruins of Nagasaki, shortly after an atomic bomb destroyed much of the city. The explosion generated heat estimated at 3,900 degrees Celsius (4,200 K, 7,000 °F). #

On August 9, 1945, the Soviet Union invaded Manchuria, sending more than a million soldiers to attack Japan's Kwantung Army. The Soviets quickly defeated the poorly-prepared Japanese, putting further pressure on them to surrender to the Allies. Here, a column of tanks appears on the streets of the Chinese city of Dalian. #

Soviet soldiers on the bank of the Songhua River in Harbin. The Japanese-occupied city was liberated by Soviet troops on August 20, 1945. Some 700,000 Soviet troops occupied Manchuria by the time Japan surrendered, #

A Japanese prisoner of war at Guam, Mariana Islands, covers his face as he hears Japanese Emperor Hirohito making the announcement of Japan's unconditional surrender on August 15, 1945. World War II had come to an end. #

The scene aboard the battleship Missouri as the Japanese surrender documents were signed in Tokyo Bay, on September 2, 1945. Here, General Yoshijiro Umezu signs the Instrument of Surrender on behalf of the Armed Forces of Japan, Foreign Minister Mamoru Shigemitsu (behind him, in top hat) had earlier signed on behalf of the government. Both men were later tried and convicted of war crimes. Umezu died while in prison, Shigemitsu was paroled in 1950, and served in the Japanese government until his death in 1957. #

Dozens of F4U Corsair and F6F Hellcat fighter planes fly in formation over the USS Missouri, while the surrender ceremonies to end World War II take place aboard the U.S. Navy battleship, on September 2, 1945. #

American servicemen and women gather in front of "Rainbow Corner" Red Cross club in Paris, France to celebrate the unconditional surrender of the Japanese. #

An allied correspondent stands in the radioactive rubble in front of the shell of a building that once was an exhibition hall in Hiroshima, Japan, one month after the first atomic bomb ever used in warfare was dropped on the city by the U.S. The explosion took place almost directly above the dome. #