The next morning, D-plus two, Company E, 2nd Battalion, 28th Marines pushed forward in the assault against the vast network of fortifications surrounding the base of Mount Suribachi. During the advance, Ruhl with his platoon guide Sergeant Henry Hansen, later famous for a mistaken belief that he was involved in raising an American flag on Mount Suribachi, crawled to the top of a Japanese bunker to bring fire to bear on enemy troops located on the far side of the bunker. Suddenly a hostile grenade landed between the two Marines. Calling a warning to Hansen, Ruhl instantly dove on the grenade and absorbed the full charge of the explosion with his body. His action not only saved Hansen but also prevented the grenade fragments from wounding other nearby Marines. Rather than using his position on the edge of the bunker to easily drop down into a more protected spot, he sacrificed his life to save his fellow Marines.