The commander of the B-29 plane that dropped the first atomic bomb, on Hiroshima in Japan, has died.
Paul Warfield Tibbets Jr died at his home in Columbus, Ohio, aged 92.
The five-ton "Little Boy" bomb was dropped on the morning of 6 August 1945, killing about 140,000 Japanese, with many more dying later.
On the 60th anniversary of the bombing, the three surviving crew members of the Enola Gay - named after Tibbet's mother - said they had "no regrets".
A friend of the retired brigadier-general told AP news agency that Paul Tibbets had died after a two-month decline in health.
Gen Tibbets had asked for no funeral nor headstone as he feared opponents of the bombing may use it as a place of protest, the friend, Gerry Newhouse, said.
The Hiroshima bomb killed about 140,000 Japanese
The bombing of Hiroshima marked the beginning of the end of the war in the Pacific.
Japan surrendered shortly after a second bomb was dropped, on Nagasaki, three days later.
On the 60th anniversary of Hiroshima, the surviving members of the Enola Gay crew - Gen Tibbets, Theodore J "Dutch" Van Kirk (the navigator) and Morris R Jeppson (weapon test officer) said: "The use of the atomic weapon was a necessary moment in history. We have no regrets".
Gen Tibbets said then: "Thousands of former soldiers and military family members have expressed a particularly touching and personal gratitude suggesting that they might not be alive today had it been necessary to resort to an invasion of the Japanese home islands to end the fighting."
Paul Warfield Tibbets Jr was born in Quincy, Illinois, in 1915 and spent most of his youth in Miami.
He enlisted in the Army Air Corps in 1937 and led bombing operations in Europe before returning to test the Superfortress.
He retired from the forces in 1966.
In a 1975 interview he said: "I'm proud that I was able to start with nothing, plan it and have it work as perfectly as it did... I sleep clearly every night."
In 1976, Gen Tibbets was criticised for re-enacting the bombing at an air show in Texas.
A mushroom cloud was set off as he over flew in a B-29 Superfortress in a stunt that outraged Japan. Gen Tibbets said it was not meant as an insult but the US government formally apologised.
In 1995, Gen Tibbets denounced as a "damn big insult" a planned 50th anniversary exhibition of the Enola Gay at the Smithsonian Institution that put the bombing in context of the suffering it caused.
He and veterans groups said too much attention was being paid to Japan's suffering and not enough to its military brutality.