 After knocking out the six machine gun positions, the Marines faced the 47 mm gun cave.A lieutenant blinded the 47 mm gunner's visibility with a smoke grenade, allowing Corporal Henry W. Hahn to launch a grenade through the cave's aperture.The grenade detonated the 47 mm's shells, forcing the cave's occupants out with their bodies alight and their ammunition belts exploding around their waists.