 While the helicopters and men of the Division were soon in position, most of their heavy and support equipment was loaded on trucks that would have to proceed by convoy up Highway 1.While a new supply port was being constructed on the coast, the Division relied on the Marine supply base at Tân Mỹ and supply convoys along Highway 1 from Da Nang.On the night of 31 January, the PAVN-VC launched a mortar attack on Camp Evans which caused an ammunition dump to explode, disabling most of the helicopters of the 229th Assault Helicopter Battalion.