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.
Bombing of Osaka
The first air raid on Osaka lasted for about three and a half hours from 23:57 on March 13, 1945, to 03:25. A total of 274 B-29 heavy bombers attacked Osaka. At first, 43 bombers of the 314th Bombardment Wing flew from Guam island. It was a low-level night raid from an altitude of about 2,000m aiming at the local civilian housings. The pathfinder dropped napalm bombs at a target in Minato ward and made a conflagration. The following bombers dropped incendiary cluster bombs around the point. Then, 107 bombers of the 313th Bombardment wing arrived from Tinian and attacked Naniwa ward. Finally, 124 bombers of the 73rd Bombardment Wing from Saipan arrived and attacked Kita ward and Nishi ward. This bomb raid resulted in 3,987 dead and 678 missing.