On 30 March 1972 the 258th Marine Brigade was deployed forward to Đông Hà.[4]: 43 Early on the morning of 1 April under pressure from the PAVN the 4th Vietnamese Marine Corps Battalion abandoned Firebase Sarge and retreated to Mai Loc Camp.[4]: 44–5 The 56th Regiment withdrew to Camp Carroll, the 57th Regiment to north of Dong Ha and the 2nd Regiment withdrew to Cam Lộ.[2]: 27 By 1 April the PAVN had broken through the ARVN defensive positions along the DMZ and north of the Cam Lo River and fragmented ARVN units and terrified civilians began withdrawing to Đông Hà.[4]: 45 General Giai, ordered a withdrawal of the Division south of the Cửa Việt River in order for his troops to reorganize a new defensive line: Regional and Popular Forces would secure the area from the coast to 5 km inland; the 57th Regiment would hold the area from there to Đông Hà ; the 1st Armored Brigade including the 20th Tank Battalion would hold Đông Hà; the 2nd Regiment reinforced by an armored cavalry squadron would hold Cam Lộ, while the 56th Regiment supported by the 11th Armored Cavalry Squadron would hold Camp Carroll. Extending the line south the 147th Marine Brigade would hold Mai Loc and secure the high ground along Route 9 between Cam Lộ and Mai Loc.[2]: 27