On July 21st 1945, the physicist William Penney, a guiding light of the later British nuclear weapons programme, held a seminar at Los Alamos, New Mexico, where the first atomic bombs were being assembled, to announce the results of his calculations on the impact of an A-bomb. A city of 300,000400,000 people, he said, would be reduced to a sink for disaster relief, bandages and hospitals.
Some 17 days after Penney's seminar, Thomas Ferebee, who died on March 16th aged 81, was one of the handpicked crew on the Enola Gay, a US army air force (USAAF) B29 superfortress, flying five miles above the Japanese city of Hiroshima. It was a sunny day, just 17 seconds after 8.15 a.m., when Ferebee, Enola Gay's bombaimer - then only 26 years old - released the first A-bomb towards the Ota river bridge.
The Hiroshima bomb had the explosive power of 12,500 tons of TNT explosives. Of a population of 350,000, between 60,000 and 70,000 people died outright. More than 50 per cent of the area simply vanished. It was not the greatest bombing devastation wreaked on a single city, but, the world had turned.
The crew watched as the radioactive cloud over Hiroshima ascended to the B29's altitude of 33,000 ft. The cloud's surface was "nothing but a black boiling", recalled the aircraft commander Col Paul Tibbets, "like a barrel of tar."
The Japanese were initially uncertain as to what had happened. So was Thomas Ferebee. It was only when he returned to his base at Tinian, in the Northern Mariana Islands, that he was told he had dropped an atomic bomb. Nagasaki was similarly attacked on August 9th. Six days later, Japan surrendered, finally ending the second World War.
Announcing that the Hiroshima attack had taken place, US President, Mr Truman, explained that the A-bomb was the "harmonising of the basic power of the universe". The Manchester Guardian editorialised that the bombing was legitimate, but that humanity had turned one of history's corners. The publisher and writer Victor Gollancz described the attacks as "a blasphemous presumption".
Later critics suggested that the raids had been primarily a demonstration of US power directed at the Soviet Union. Thomas Ferebee himself did not regret the bombing; he argued it had saved the million lives that an invasion of Japan would have cost.
The bomb-aimer had provided the US with its punctuation mark on the 20th century; confirming its monoply both of global reach - no other country had an intercontinental bomber like the B29 - and briefly, of nuclear weapons. The A-bomb had been developed by scientists from many nations, but the funds and direction came from the US.
Thomas Ferebee was a farmer's son, one of 11 children, born outside the small town of Mocksville, near Winston-Salem, North Carolina. Educated at the local Lees-McRae college, he excelled at sports, trained with the Boston Red Sox and had early hopes of a baseball career. A knee injury precluded him from army service, and in 1940 he joined the USAAF.
From 1942-44, he was based in England, flying 63 missions. These included the first USAAF daylight raid on France; later, he was part of the attack on the Nazi-controlled oil fields at Ploesti, in Romania. His pilot on those missions was Paul Tibbets, who chose him when the 509th Composite Group was formed for the A-bomb mission late in 1944.
After the war, Thomas Ferebee stayed on in the military. As deputy wing-commander for maintenance, he worked with the US air force on B47 bombers, and during the Vietnam war flew on B52s. He retired in 1970 and became an estate agent in Florida. The world he inadvertently summoned into being persists - in nuclear arsenals, and 747 jumbo jets and B52s, the direct descendants of the Boeing B29.
In retirement, he enjoyed cultivating roses. He is survived by his second wife, Mary-Ann, whom he married 19 years ago, and by four sons from his first marriage.
Thomas Wilson Ferebee: born 1918; died March, 2000 99104754