Bockscar took off on 9 August, with Fat Man on board. This time, the primary target of Kokura was obscured by dense smoke left over from the earlier B-29 raid on nearby Yawata, and the bombardier could not pinpoint the specified aiming point despite three separate runs. So Sweeney turned to the secondary target, Nagasaki. There were clouds over Nagasaki as well, and a couple of runs over the target had to be made before the bombardier could find an opening in the clouds. At 11:00 am, Fat Man was released from the aircraft and after a long descent, the bomb exploded. The yield was estimated at 22 kilotons of TNT. Approximately 35,000 people died at Nagasaki from the immediate blast and fire.