 On that day, 2,000 North Vietnamese Army regulars attacked in force from all sides of the camp. Other hostile forces laid down a devastating barrage of mortars and automatic weapons fire from the surrounding hills. The tops of the 1,500-high-foot hills were obscured by an 800-foot ceiling, limiting aircraft maneuverability and forcing pilots to operate within range of the enemy gun positions, which often were able to fire down on the attacking aircraft.