When his unit was attacked by a North Vietnamese battalion near Polei Doc, First Sergeant David H. McNerney ran through heavy enemy fire to the area of heaviest contact and helped develop a defensive perimeter. After encountering several enemy at close range and killing them, he was painfully injured by a grenade blast, yet he went on to assault and destroy an enemy machine gun position that had pinned down five comrades beyond the defensive line. After his commander and artillery forward observer were killed, he assumed command of the company and adjusted artillery fire to within twenty meters of the position to help repulse enemy assaults. When smoke grenades used to mark the position were exhausted, he moved into a nearby clearing to identify the location to friendly aircraft, remained exposed under enemy fire until the position was spotted, then climbed a tree and tied an identification panel to its highest branches. He then moved among his men to readjust their positions, encourage the defenders, and check the wounded. As the assaults slackened, he began clearing a helicopter landing site to evacuate the wounded, and when explosives were needed to remove large trees, he crawled outside the perimeter to collect demolition material from abandoned rucksacks and returned through intense fire with the explosives needed to clear the landing zone. Despite his injury and despite refusing medical evacuation, he remained with his unit until the next day, when a new commander arrived.