Hiroshima: Terror marks the dawn of the nuclear age
In a blinding, petrifying instant a terrifying new chapter opened in the bloody history of warfare and of humanity in general.
On August 6, 1945 at 8:15 am the United States unleashed the world's first nuclear weapon on Hiroshima, Japan, killing 140,000 people. Three days later a second bomb devastated Nagasaki, forcing Japan to surrender and bringing World War II to an end.
Here is an account of four days that demonstrated the terrible power of nuclear bombs to the entire world, setting the stage for a frantic arms race and the subsequent Cold War.
- Airborne -
The B-29 bomber Enola Gay took off from a US airbase on Tinian, in the Pacific chain of Marianas Islands. It carried 12 crew members. Only the pilot, Colonel Paul Tibbets, knew the actual target.
The plane held just one bomb, built with a uranium 235 warhead and dubbed "Little Boy" even though it weighed 9,000 pounds (four metric tons). The bomb was armed once the plane was airborne to prevent the island from being completely destroyed if the heavily laden B-29 crashed upon takeoff. Three other planes had taken off from Tinian an hour earlier to check weather conditions over potential targets.
Around 8:00 am visibility was clear over Hiroshima. Tibbets ordered the bomb drop at 8:15 am and immediately turned his plane away. It was flying at an altitude of 9,000 metres (29,500 feet). Exactly 51 seconds later, "Little Boy" exploded 600 metres (1,800 feet) above the ground.
"While that bomb was in the process of falling and I was making this turn, I'd say that was the longest 45 seconds that I ever lived, because the question was, 'Is it gonna blow, did anything go wrong, have I made a mistake'?" Tibbets said later in an interview.
An enormous ball of fire lit up the sky over Hiroshima and quickly became a dense white cloud that rose to 15,000 metres (49,000 feet).
On the ground, terrified witnesses spoke later of seeing a violent burst of light ("Pika") or a flash followed by an explosion ("Pikadon"), depending on where they were when the bomb exploded.
Japanese doctor Shuntaro Hira said: "The massive cloud rose, grandiose and splendid, to crush all of Hiroshima under its column of flame."
The city was chosen as a target because it was home to a huge military base and housed the headquarters of Japan's homeland defence command.
It had been spared firebombings that hit other Japanese cities, such as one in March 1945 that killed about 100,000 in Tokyo.
Most of Hiroshima's 300,000 inhabitants had ignored an air-raid warning that was triggered at 7:31 am when the lead US weather plane was seen overhead, and many were heading to school, work and military installations when the detonation took place.
- Tens of thousands of radiation victims -
The shock wave demolished buildings made of reinforced concrete and annihilated traditional homes. Heat generated by the bomb at "ground zero" has been estimated at several thousand degrees Centigrade and tens of thousands of people near the centre of the explosion simply vaporized.
Within a radius of three kilometres (two miles) from the epicentre, roof tiles and metal structures melted and trees burst into flames. Haggard and horribly burned survivors screamed in pain before collapsing to the ground.
In the following days, a great number of those who survived the initial shock wave succumbed to radiation poisoning. Victims suffered violent haemorrhaging and heavy sweating.
In addition to the 140,000 who died by the end of December 1945 due to the explosion, according to generally accepted estimations, tens of thousands more died later from injuries or radiation.
In Washington, the White House published a statement by President Harry Truman:
"Sixteen hours ago an American plane dropped one bomb on Hiroshima and destroyed its usefulness to the enemy," it said.
"It is an atomic bomb. It is a harnessing of the basic power of the universe."
Truman gave Japanese leaders an ultimatum: "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."
But neither the Japanese emperor nor government replied to the US demands.
Three days later the US Army Air Force dropped a second bomb built around a plutonium core and nicknamed "Fat Man" on Nagasaki, killing some 74,000 people.
The Japanese government conceded defeat and Emperor Hirohito addressed the nation on August 15. The formal surrender document was signed on September 2 on the battleship USS Missouri. The atomic bomb had brought the world's most brutal war to an end but it had also revealed the nuclear threat.
More than 70 years later Hiroshima has been rebuilt and stands as a living symbol of one of history's great tragedies. Japan has repeatedly called for the elimination of all nuclear weapons around the globe.