 Shortly after midnight on 18 July, PAVN artillery, rockets and mortar rounds began exploding on the defenses and outposts of Da Trach.A relatively weak attack by the PAVN 2nd Battalion, 36th Regiment, on the camp's main defenses was beaten back with heavy losses to the PAVN and light casualties to the defenders, but contact with the 2nd Company, 3rd Battalion, 56th Infantry, outposts at Khuong Que and Cua Tan was lost before daybreak.By that time, the 4th Company, 146th RF Battalion at Ap Ba had been attacked and overrun, and the survivors were trying to escape through the mountains toward Duc Duc headquarters.