By 4 September it had become quite clear that the N.K. 3d Division in front of the 5th and 7th Cavalry Regiments was itself attacking, and that, despite continued air strikes, artillery preparations, and infantry efforts on Hill 518, it was infiltrating large numbers of its troops to the rear of the attacking United States forces. That day the I&R Platoon reported that enemy soldiers held Hill 464, a high hill mass opposite Hill 518 on the south side of the Waegwan-Tabu-dong road, and that it had to destroy its radio and machine gun to keep them from falling into enemy hands.
That night large enemy forces came through the gap between the 3d Battalion on the southern slope of Hill 518 and the 2d Battalion westward. For a time those in the 3d Battalion command post thought the attack was going to turn east and overrun them but, instead, the North Koreans turned west and occupied Hill 464 in force.