Map No. 11: The Pinnacle
Whatever its strength in feudal times, the castle was good now only for one day's defense by the Japanese. On the morning of 5 April, the 7th Division found that the heights had been deserted before daylight. The division registered long advances during the day. The 32d Infantry moved more than two miles along the coast to a point east of Ukuma. The 184th advanced through Arakachi, and then was brought to a standstill by heavy and accurate fire from a rocky pinnacle located about 1,000 yards southwest of Arakachi. Company B, 184th Infantry, assaulted the hill on the 5th but was driven back. The reduction of this position-called the Pinnacle after a thin coral spike that rose 30 feet above the 450-foot ridge and served as a watchtower for the Japanese-was to be the main task of the 7th Division on the following day.
It was probably on this very hill that a party of Americans from Commodore Perry's expedition in 1853 raised the American flag "with hearty cheers" while exploring the island.{191}The Japanese had selected the Pinnacle as an important outpost position because it dominated the adjoining ground and afforded excellent observation in all directions. Holding the Pinnacle was 1st Lt. Seiji Tanigawa's 1st Company, 24th Independent Infantry Battalion, composed of company headquarters and two rifle platoons, a total of 110 men. The third platoon was a mile to the rear in battalion reserve.
Lieutenant Tanigawa had built his defenses around eight light and two heavy machine guns sited at the base of the hill. In trenches and pits riflemen well-supplied with grenades covered the dead spaces in front of the machine guns. The defenses were connected by the usual tunnels and trenches, affording underground mobility. On the top of the ridge were four 50-mm. mortars, and on the reverse slope to the south were three more. Artillery check points had been established for 62d Division field pieces to the south. Barbed wire and mine fields protected the major approaches. Lieutenant Tanigawa could hardly have hoped to stop the Americans, but undoubtedly he expected to make the price of victory high. (See Map No. 11.)
After a 10-minute artillery preparation on the morning of 6 April, Company B, 184th Infantry, made a frontal assault on the Pinnacle, supported on the right (west) by Company C. Two platoons climbed almost to the top of the ridge, but when they started dropping grenades into caves and underground positions they stirred up a hornet's nest. The Japanese fought back with grenades, satchel charges, and mortars. The troops held on for fifteen minutes, until mounting casualties forced a withdrawal. An hour later another infantry assault was attempted, supported by 105-mm. artillery, light tank fire, antitank guns, heavy machine guns, 60-mm. and 81-mm. mortars, 4.2-inch chemical mortars, and bazookas; but the attack was again stopped by Japanese who hid underground during the heavy fire and then rushed back to their firing positions to meet the oncoming Americans.
For the third attack of the morning, Lt. Col. Daniel G. Maybury, commanding the 1st Battalion, 184th Infantry, decided to push Company C up a draw just beyond the ridge used by Company B, but the latter was still expected to seize the peak. Company B moved up the ridge quickly to catch the enemy out of his holes, but again the troops were driven back. Company C was now working its way up the western approaches along a difficult but partially covered route. Lieutenant Tanigawa had directed the repulse of Company B from the Pinnacle watchtower but he did not know of Company C's approach on his flank. Colonel Maybury directed supporting fire in front of Company C, which quickly moved to the top without losing a man. It then proceeded leisurely and methodically to destroy the remaining Japanese with white phosphorus grenades and flame throwers. Only 20 of the 110 defenders escaped to the south. With the Pinnacle reduced, the entire 7th Division line could move forward.
The Pinnacle had been a tough position to crack, yet it was only an outpost. The Pinnacle was undermanned, and no reinforcements were provided. During the action Lieutenant Tanigawa pleaded with his superiors for artillery support, but he was provided with neither the artillery nor an explanation of the refusal. By 6-7 April the XXIV Corps had unmasked the Shuri fortified zone, composed of many positions as fanatically defended as Pinnacle outpost and also heavily supported by artillery and fed by an almost endless stream of reinforcements from local reserve units.
Assault units of the XXIV Corps had by 6 April penetrated the outposts held by the 12th Independent Infantry Battalion and were in contact with two other battalions of the 63d Brigade of the 62d Division. In general, the 13th Independent Infantry Battalion faced the 96th Division; the 14th opposed the 7th Division; and remnants of the 12th, which had suffered heavily in its outpost actions to the north, straddled the division boundary in the center of the island. The Japanese Independent Infantry Battalion was well adapted for outpost action. Each of its five rifle companies was equipped with nine light machine guns and nine grenade dischargers; the machine gun company operated ten heavy machine guns; and the infantry gun company was furnished with two 75-mm. regimental guns and two 70-mm. howitzers. Each of the three battalions had originally a strength of about 900, but Okinawan conscripts and Boeitai swelled the total to approximately 1,200.{192}
EAST COAST BATTLES of the 184th Infantry, 7th Division, in early April centered about the hill called the Pinnacle. Its western approaches, over which Company C moved to capture it, are shown above. At high point on right is watchtower. From the Pinnacle the 2d Battalion, 184th, attacked toward Tomb Hill along the finger ridge shown in the center of the picture below. A white phosphorus shell had just burst on the hill beyond.