However great the cost, Bloody Ridge was now won for good. There was little fight left in the scattered groups of Japanese still occupying the center of the town below Iegusugu. The 3d Battalion, 307th Infantry, relieved the 2d during the morning and began mopping up positions and sealing caves around Government House Hill. The 3d Battalion, 305th, which had broken up an attack on its north flank by two platoons of Japanese at dawn of 21 April and killed thirty of the enemy, finally made a successful attack east into the town of Ie. The troops moved forward again after a short artillery preparation. In three hours the battalion destroyed twelve separate emplacements, chiefly by means of flame throwers, bazookas, and pole charges, and gained a line running south from the small lake at the southwest base of Iegusugu. The Pinnacle at last lay open to attack from the south.
The three battalions of the 306th tightened their grip on Iegusugu during the morning of 21 April. The 3d Battalion assaulted the east slopes at 0830, and the 1st and 2d Battalions continued to reduce caves and pillboxes on the north and northwest slopes. Early in the morning a patrol from the 1st Battalion scaled a 50-foot cliff under sniper fire, and at 1025 a member of the patrol flew the American flag from his hands at the very tip of Iegusugu. Increased sniper fire from the lower slopes prevented others from bringing up a flagpole and ultimately forced the men off the peak.
Fierce fighting continued on the sides of the Pinnacle as the infantrymen tightened their grip during the remainder of 21 April. The battalions were now so close to one another that careful coordination was necessary to prevent troops from firing on friendly units. General Randle ordered successive attacks so that one battalion could attack while others took cover. The 3d Battalion, 306th, reduced a strong position on its left (south) flank, and at 1030 established contact with the north flank of the 1st Battalion, 305th. Shortly after noon the 3d Battalion of the 307th, on the west, and the 1st Battalion of the 305th, on the east, attacked north from their positions on Bloody Ridge to gain the southern slopes of Iegusugu. Resistance was slight and the slopes were reached at 1300. The attack crossed the front of the 3d Battalion, 305th, which was pinched out. The 1st Battalion, 305th, was also pinched out when its zone of action narrowed. The 3d Battalion, 307th, was now between the 2d Battalion, 306th, on the left (west), and the 3d Battalion, 306th, on the right. "All organized resistance crushed," General Randle notified General Bruce at 1345{254}
Disorganized resistance, however, continued. The southwest slopes of Iegusugu were still in enemy hands. At 1400 Company E on the right (south) flank of the 2d Battalion, 306th, made a coordinated attack with elements of the 3d Battalion, 305th, to push on to the southwest side. The attacking troops immediately came under fire from emplacements still occupied by the enemy. It was no longer possible to use artillery, the area still held by the Japanese being too small. Naval gunfire support had ceased on 19 April for the same reason. Even the use of self-propelled 75-mm. howitzers was limited. With small arms, grenades, flame throwers, and demolitions, the troops cleaned the Japanese from their positions on the steep slopes. Two tanks were brought up to help knock out a large fortified cave about halfway up the mountain. By 1445 the troops attacking from the west had seized their assigned area.
By midafternoon of 21 April all units on the Pinnacle were engaged in mopping up. The exterior of the Pinnacle was secure, but Japanese still remained in subterranean passages and strongholds from which they made sallies against the troops. The openings were systematically blown out and sealed off. The 307th alone captured or destroyed during the day five 81-mm. mortars, five knee mortars, one 75-mm. howitzer, and two 47-mm. antitank guns. These were some of the weapons that had held the Americans off Bloody Ridge for three days.
At 1730 on 21 April, Ie Shima was declared secure. "The last three days of this fighting were the bitterest I ever witnessed," General Bruce stated when the operation was over.{255}
For five days after Ie Shima was declared secure, elements of the 77th mopped up remaining groups of the enemy, sealed caves, destroyed pillboxes, marked or removed the thousands of mines that were still on the island, and buried the dead. During this period hundreds of Japanese were killed in and around the Pinnacle, in the town of Ie, and in caves along the coast line. Removal of mines on the airfield and on the roads feeding it was given priority in order to speed up airfield construction. The last noteworthy encounter on Ie Shima came during the night of 22-23 April, when a group of Japanese soldiers and civilians, including women, all armed with rifles, grenades, and demolitions, rushed from caves on Iegusugu toward the lines of the 306th. They were all cut down without loss to American troops.
During the 6-day battle on Ie Shima the Americans killed 4,706 Japanese and took 149 prisoners. Many of the dead were civilians; it was extremely hard to distinguish between soldiers and civilians during the fighting or when inspecting the bodies afterwards. It was estimated that 1,500 civilians had been armed and supplied with Japanese Army uniforms. Some others were in American uniforms. The amount of enemy materiel destroyed will never be known, since so much of it was buried by gunfire, sealed up in caves, or simply blown to pieces. Among the destroyed or captured materiel actually counted were 34 mortars, 44 light machine guns, 8 heavy machine guns, 4 antitank guns, 5 antiaircraft guns, more than 5,000 mines of assorted types, and several crates of parts for suicide rocket planes.
American casualties through 24 April were reported as 172 killed in action, 902 wounded, and 46 missing-a total of 1,120. According to the division surgeon, "casualties on Ie Shima were unusually severe, many of them compound fractures of the extremities and penetrating head wounds caused by small-arms fire." Out of 944 cases, he reported, 412 wounds had been caused by small-arms fire, 511 by shell fragments, and 21 by other causes.{256} Losses in materiel and ammunition expenditures also were high for such a short engagement. Of sixty medium tanks and six 105-mm. assault guns, five were completely destroyed by enemy mines, hand-placed satchel charges, or antitank guns, and many others were temporarily neutralized. During the operation almost 5,000 75-mm. and 105-mm. shells were fired from tanks and SPM's and over 2,500 rounds of 37's and 75's from amtracks. Despite restrictions on the use of heavier fire because of the proximity of the units during the latter part of the fighting, division artillery fired 16,023 rounds of 105-mm. and 155-mm. shells.
"We have gained at relatively low cost in men, materials, and time what will soon be the most valuable eleven square miles of land in the far western Pacific," the 77th Division reported optimistically at the conclusion of the engagement.{257}
Base development proceeded rapidly once the mopping up was completed. Although initially delayed by the large number of mines, the engineers quickly repaired the enemy airfield and began the construction of new strips. The coral foundation of the island and the rubble of the town of Ie facilitated the work. There was ample room for dispersal area, and the sloping ground on the sides and ends of the central plateau provided space for housing base personnel. Civilians were evacuated to Tokashiki in the Keramas. Engineers discovered a large limestone basin on the north coast which produced 100,000 gallons of fresh water; at high tide each day the basin filled up with water filtered by nature. Under these conditions work proceeded rapidly and by 10 May one fighter group was based on the island. By the middle of the month all taxiways and runways were fully operational and radar and air warning facilities installed, although much construction work remained. By 14 June three fighter groups and one night fighter squadron were operating from the airfield. As expected, Ie Shima proved to be an ideal base for the support of operations on Okinawa and for preparing later attacks on the Japanese homeland.