<P> At first it came as a ragged rattle of machine - gun bullets, growing gradually lower and fiercer until at last all the pent - up fury of a hundred hurricanes seemed to be breaking upon the heads of the Americans . Shells screeched and crashed, every hummock spat automatic fire and the very soft soil underfoot erupted underfoot with hundreds of exploding land mines...Marines walking erect crumpled and fell . Concussion lifted them and slammed them down, or tore them apart...</P> <P> Time - Life correspondent Robert Sherrod described it simply as "a nightmare in hell ." </P> <P> The Japanese heavy artillery in Mount Suribachi opened their reinforced steel doors to fire, and then closed them immediately to prevent counterfire from the Marines and naval gunners . This made it difficult for American units to destroy a Japanese artillery piece . To make matters worse for the Americans, the bunkers were connected to the elaborate tunnel system so that bunkers that were cleared with flamethrowers and grenades were reoccupied shortly afterwards by Japanese troops moving through the tunnels . This tactic caused many casualties among the Marines, as they walked past the reoccupied bunkers without expecting to suddenly take fresh fire from them . </P> <P> In response to the heavy resistance on the beach, the Army's 147th Infantry Regiment was ordered to climb from landing craft with grappling hooks to scale a high ridge about 3 / 4 mile from Mount Suribachi . The mission was to fire on the enemy opposing the Marine landings on the beaches below . They were soon pinned down by heavy Japanese fire, and engaged in non-stop fighting for 31 days before they could be relieved . </P>

Where did the battle of iwo jima take place