 The original target for the bomb was the city of Kokura, but it was found to be obscured by clouds and drifting smoke from fires started by a major firebombing raid by 224 B-29s on nearby Yawata the previous day. This covered 70 % of the area over Kokura, obscuring the aiming point. Three bomb runs were made over the next 50 minutes, burning fuel and repeatedly exposing the aircraft to the heavy defenses of Yawata, but the bombardier was unable to drop visually. By the time of the third bomb run, Japanese anti-aircraft fire was getting close, and Second Lieutenant Jacob Beser, who was monitoring Japanese communications, reported activity on the Japanese fighter direction radio bands.
