day, two naval bombardment groups led by Rear Admiral Jesse B. Oldendorf arrived on the shore of Saipan. This force was the main naval fire support for the seizure of the island and consisted of 7 older battleships, 11 cruisers, and 26 destroyers, along with destroyer transports and fast minesweepers. The old battleships, commissioned between 1915 and 1921, were trained in shore bombardment and were able to move into closer range. Four of them (, , and ) were survivors of the attack on Pearl Harbor. The landings began at 07:00 on 15 June 1944. More than 300 LVTs landed 8,000 Marines on the west coast of Saipan by about 09:00. Eleven fire support ships covered the Marine landings. The naval force consisted of the battleships Tennessee and California, the cruisers and , the destroyers , , , , , , and . Careful artillery preparation — placing flags in the lagoon to indicate the range — allowed the Japanese to destroy about 20 amphibious tanks, and they had placed barbed wire, artillery, machine gun emplacements, and trenches to maximize the American casualties. However, by nightfall, the 2nd and 4th Marine Divisions had a beachhead about wide and deep. The Japanese counter-attacked at night but were repelled with heavy losses. On 16 June, units of the U.S. Army's 27th Infantry Division landed and advanced on the airfield at Ås Lito. Again the Japanese counter-attacked at night. On 18 June, Saito abandoned the airfield. The invasion surprised the Japanese high command, which had been expecting an attack further south. Admiral Shigetarō Shimada, Commander-in-Chief of the Imperial Japanese Navy (IJN), saw an opportunity to use the A-Go force to attack the U.S. Navy forces around Saipan. On 15 June, he gave the order to attack. But the resulting battle of the Philippine Sea was a disaster for the IJN, which lost three aircraft carriers and hundreds of planes. Without resupply, the battle on Saipan was hopeless for the defenders, but the Japanese were determined to fight to the last man. Saitō organized his troops into a line anchored on Mount Tapochau in the defensible mountainous terrain of central Saipan. The nicknames given by the Americans to the features of the battle — "Hell's Pocket", "Purple Heart Ridge" and "Death Valley" — indicate the severity of the fighting. The Japanese used many caves in the volcanic landscape to delay the attackers, by hiding