Readjusting the front lines of XXIV Corps to allow room for the 27th Division took time; so did building up adequate units of fire for field artillery battalions to support the mammoth, three-division offensive General Buckner wanted. A week of general inactivity passed along the southern front, which inadvertently allowed the Japanese to make their own adjustments and preparations for the coming offensive. On 18 April (L plus 17) Buckner moved the command post of the Tenth Army ashore. The offensive began the next morning, preceded by the ungodliest preliminary bombardment of the ground war, a virtual “typhoon of steel” delivered by 27 artillery batteries, 18 ships, and 650 aircraft. But the Japanese simply burrowed deeper into their underground fortifications and waited for the infernal pounding to cease and for American infantry to advance into their well-designed killing traps.
Department of Defense Photo (USMC) 116356
Two Marines help an aged Okinawan to safety in the rear of the lines, as a third Marine of the party carries the man’s meager possessions. Only children, women, and the aged and infirm were found and protected by assaulting Marines as they pushed across the island during the first few days following the 1 April landing.
The XXIV Corps executed the assault on 19 April with great valor, made some gains, then were thrown back with heavy casualties. The Japanese also exacted a heavy toll of U.S. tanks, especially those supporting the 27th Infantry Division. In the fighting around Kakazu Ridge, the Japanese had separated the tanks from their supporting infantry by fire, then knocked off 22 of the 30 Shermans with everything from 47mm guns to hand-delivered satchel charges.
The disastrous battle of 19 April provided an essential dose of reality to the Tenth Army. The so-called “walk in the sun” had ended. Overcoming the concentric Japanese defenses around Shuri was going to require several divisions, massive firepower, and time—perhaps a very long time. Buckner needed immediate help along the Machinato-Kakazu lines. His operations officer requested General Geiger to provide the 1st Tank Battalion to the 27th Division. Hearing this, General del Valle became furious. “They can have my division,” he complained to Geiger, “but not piece-meal.” Del Valle had other concerns. Marine Corps tankers and infantry trained together as teams. The 1st Marine Division had perfected tank-infantry offensive attacks in the crucible of Peleliu. Committing the tanks to the Army without their trained infantry squads could have proven disastrous.
Fortunately, Geiger and Oliver P. Smith made these points clear to General Buckner. The Tenth Army commander agreed to refrain from piece-meal commitments of the Marines. Instead, on 24 April, he requested Geiger to designate one division as Tenth Army Reserve and make one regiment in that division ready to move south in 12 hours. Geiger gave the mission to the 1st Marine Division; del Valle alerted the 1st Marines to be ready to move south.
These decisions occurred while Buckner and his senior Marines were still debating the possibility of opening a second front with an amphibious landing on the Minatoga Beaches. But the continued bloody fighting along the Shuri front received the forefront of Buckner’s attention. As his casualties grew alarmingly, Buckner decided to concentrate all his resources on a single front. On 27 April he assigned the 1st Marine Division to XXIV Corps. During the next three days the division moved south to relieve the shot-up 27th Infantry Division on the western (right) flank of the lines. The 6th Marine Division received a warning order to prepare for a similar displacement to the south. The long battle for Okinawa’s southern highlands was shifting into high gear.
Meanwhile, throughout April and with unprecedented ferocity, the Japanese kamikazes had punished the ships of the Fifth Fleet supporting the operation. So intense had the aerial battles become that the western beaches, so beguilingly harmless on L-Day, became positively deadly each night with the steady rain of shell fragments from thousands of antiaircraft guns in the fleet. Ashore or afloat, there were no safe havens in this protracted battle.