 As the Marines commenced a slow and difficult descent down the side of the hill, made extremely slippery by the heavy rains, the leading element came under a heavy fire from a North Vietnamese Army unit occupying well-concealed positions in the rocky terrain.Four men were wounded, and repeated attempts to recover them failed because of the intense hostile fire.Lance Corporal Noonan moved from his position of relative security and, maneuvering down the treacherous slope to a location near the injured men, took cover behind some rocks.