Charles Sweeney
Poor bombing visibility and an increasingly critical fuel shortage eventually forced "Bockscar" to divert from Kokura and attack the secondary target, Nagasaki. As they approached Nagasaki, the heart of the city's downtown was covered by dense cloud, and Sweeney and the plane's weaponeer, Commander Ashworth, initially decided to bomb Nagasaki using radar. However, a small opening in the clouds allowed "Bockscar's" bombardier to verify the target as Nagasaki. As the crew had been ordered to drop the bomb visually if possible, Sweeney decided to proceed with a visual bomb run. "Bockscar" then dropped "Fat Man", with a blast yield equivalent to 21 kilotons of TNT. It exploded 43 seconds later at above the ground, at least northwest of the planned aim point. The failure to drop "Fat Man" at the precise bomb aim point caused the atomic blast to be confined to the Urakami Valley. As a consequence, a major portion of the city was protected by the intervening hills, and only 60% of Nagasaki was destroyed. The bombing also severed the Mitsubishi arms production extensively and killed an estimated 35,000-40,000 people outright, including 23,200-28,200 Japanese industrial workers, 2,000 Korean slave laborers, and 150 Japanese soldiers.
Air raids on Japan
Hiroshima was attacked on 6 August. At 8:15 am local time the B-29 "Enola Gay", piloted by Tibbets, dropped the "Little Boy" atomic bomb over the center of the city. The resulting explosion killed tens of thousands of people and destroyed about of buildings. The six American aircraft involved in this attack returned safely to the Marianas. Postwar estimates of casualties from the attack on Hiroshima range from 66,000 to 80,000 fatalities and 69,000 to 151,000 injured. Tens of thousands more subsequently died as a result of radiation and other injuries from the attack; it has been estimated that 140,000 people had died as a result of the atomic bomb by the end of 1945. Estimates of the total number of fatalities range as high as 230,000. Of the survivors of the bombing, 171,000 were rendered homeless.