He was an acting squad leader when heavy machine-gun fire from enemy positions, well dug-in on commanding ground and camouflaged by haystacks, stopped his company's advance and pinned down one platoon where it was exposed to almost certain annihilation. Ordered to rescue the beleaguered platoon by neutralizing the German automatic fire, he led his squad forward along a draw to the right of the trapped unit against three key positions which poured murderous fire into his helpless comrades. When within range, his squad fired tracer bullets in an attempt to set fire to the three haystacks which were strung out in a loose line directly to the front, 75, 150, and 250 yards away. Realizing that this attack was ineffective, Sgt. Harmon ordered his squad to hold their position and voluntarily began a one-man assault. Carrying white phosphorus grenades and a submachine gun, he skillfully took advantage of what little cover the terrain afforded and crept to within 25 yards of the first position. He set the haystack afire with a grenade, and when two of the enemy attempted to flee from the inferno, he killed them with his submachine gun. Crawling toward the second machine-gun emplacement, he attracted fire and was wounded; but he continued to advance and destroyed the position with hand grenades, killing the occupants. He then attacked the third machine gun, running to a small knoll, then crawling over ground which offered no concealment or cover. About halfway to his objective, he was again wounded. But he struggled ahead until within 20 yards of the machine-gun nest, where he raised himself to his knees to throw a grenade. He was knocked down by direct enemy fire. With a final, magnificent effort, he again arose, hurled the grenade and fell dead, riddled by bullets. His missile fired the third position, destroying it. Sgt. Harmon's extraordinary heroism, gallantry, and self-sacrifice saved a platoon from being wiped out, and made it possible for his company to advance against powerful enemy resistance.