After the take off from Kadena Air Base, Okinawa, at 19:00 hrs of September 12, the bomber force suffered its first setback when an unexpected cold front over Korea caused icing in the upper surfaces of wings and fuselage of some B-29s. A 19th Bomb Group bomber stalled and crashed 21 miles (35 kilometers) southwest of Kangnung, killing all but one of its crew. The flak suppression forces were able to locate and attack only eight searchlights, and flak shot down an F4U of VF-193.