 In many cases, the North Koreans fought to the last man, but after suffering a two-day assault by the American 1st Cavalry Division and the 5th Regimental Combat Team, including three flights of U.S. Air Force F–51 Mustang fighters dropping napalm, firing rockets, and strafing runs, they lost the hill.With the loss of these key positions, the 3rd Division's defenses around Waegwan broke apart and its troops began a panic-stricken retreat across Naktong.Aerial observers estimated that 1.500 North Koreans crossed to the west side of the Naktong just above Waegwan.