 As a result, the Air Force began attacking previously excluded targets in the north.On 13 May 1953, Thunderjets from the 58 FBW struck the Toksan Dam, near Pyongyang causing a massive flood.Floodwaters from the breached dam destroyed ten bridges, ruined several square miles of rice crops, flooded over 1,000 buildings and rendered the Sunan Airfield inoperable.