▁( AR V N ) ▁ 2 nd ▁Regiment ▁to ▁occup y ▁the ▁area ▁around ▁D ai ▁Do ▁() ▁ 2 . 5 ▁km ▁n ortheast ▁of ▁ Đ ô ng ▁H à . ▁The ▁P AV N ▁moved ▁into ▁a ▁series ▁of ▁pre - built ▁mut ually ▁supporting ▁b unk ers ▁surrounded ▁by ▁bar bed ▁wire ▁which ▁had ▁been ▁built ▁over ▁the ▁preceding ▁weeks ▁un not iced ▁by ▁the ▁AR V N ▁who ▁were ▁responsible ▁for ▁security ▁in ▁the ▁area . ▁ ▁At ▁ 0 3 : 3 0 ▁on ▁ 3 0 ▁April ▁P AV N ▁in ▁the ▁ham let ▁of ▁An ▁Loc ▁() ▁fired ▁on ▁a ▁United ▁States ▁Navy ▁P BR , ▁which ▁returned ▁fire ▁and ▁then ▁returned ▁to ▁ Đ ô ng ▁H à ▁Base . ▁At ▁ 0 4 : 0 0 ▁the ▁P AV N ▁opened ▁fire ▁on ▁an ▁L C U ▁causing ▁severe ▁damage ▁and ▁killing ▁ 1 ▁sail or . ▁At ▁ 0 7 : 0 0 ▁a ▁pat rol ▁from ▁Company ▁H , ▁ 2 / 4 ▁Mar ines ▁operating ▁north ▁of ▁D ai ▁Do ▁was ▁sent ▁to ▁investigate ▁the ▁area . ▁Two ▁pl ato ons ▁from ▁Company ▁F ▁were ▁ordered ▁ab o ard ▁AM TR AC s ▁to ▁move ▁to ▁join ▁Company ▁H . ▁As ▁Company ▁H ▁advanced ▁towards ▁the ▁sus pected ▁P AV N ▁position ▁they ▁came ▁under ▁heavy ▁machine ▁gun , ▁mort ar ▁and ▁ro cket ▁fire ▁from ▁across ▁a ▁stream ▁in ▁the ▁ham let ▁of ▁D ong ▁X uan ▁(