Supported by nine light tanks, the 3d Battalion led the assault of the 32d Regiment against the 306th Infantry, 77th Division, before dawn on 4 May. The enemy mounted his assault from southeast of Hill 187 and hit the 77th where Route 5 curled around the east end of Urasoe-Mura Escarpment. The Japanese drove into the front lines of the 1st Battalion, 306th, near Maeda. Although the enemy found the weak points of the line, American automatic fire split up the attacking forces. As in the case of their right "spearhead," the Japanese were unable to move into the American lines at any place with sufficient force to break through. The enemy's only success consisted of driving a platoon off one of the hills. American artillery was called in against the Japanese tanks. Several were knocked out, and, as the infantry stalled, the rest withdrew.{358}
Shortly before daylight, when the Japanese infantry had failed to take its initial objectives east of Hill 187, Colonel Murakami, commanding the 27th Tank Regiment, became impatient and recklessly committed his own infantry company, a standard element of a Japanese tank regiment. American artillery fire destroyed one platoon, disrupting the attack, and daylight found the surviving troops in a precarious position across from the American lines. Colonel Murakami ordered the company to withdraw, but artillery fire prevented a retreat during the day. When the Japanese used smoke for concealment, the Americans simply blanketed the obscured area with shell fire. The survivors straggled back to their front lines after nightfall. All the light tanks that had supported the attack were lost.{359}
By 0730 the 306th Infantry had driven off the enemy. Broken up into small groups, the Japanese tried to pull back over ground swept by tremendous volumes of artillery and mortar fire, but few got through. Continued attack was impossible. At 0800 the commander of the Japanese 3d Battalion radioed the 32d Regiment command post at Dakeshi: "Although the front lines on the high ground southeast of Maeda advanced to the line of the central sector and are holding, further advance is very difficult due to enemy fire. There is no tank cooperation."{360}
On 4 May, for the first time in the campaign, whole batteries of enemy artillery were visible. By bringing his field pieces out into the open the enemy was able to deliver more than 13,000 rounds onto American lines in support of the attack. He ringed his artillery with antiaircraft guns, chiefly 75-mm., to keep off cub planes, and he used smoke pots to hide the flashes of the firing. This gamble proved to be a costly failure. By taking advantage of area artillery barrages which drove Japanese antiaircraft crews to cover, American cub planes were able to pinpoint many Japanese artillery positions for precision fire. During 4 May American counterbattery destroyed nineteen enemy artillery pieces and during the next two days forty more. The Japanese thereupon moved their remaining weapons back into caves. With the lessening of Japanese artillery fire, the number of combat fatigue cases among American troops dropped correspondingly.{361}
The Japanese effort in the air on 4 May was more successful. From dawn to 1000 American naval forces were under continuous attack by enemy planes using Kamikaze tactics, and many of the light units were sunk or damaged. Four planes crashed into the U.S. destroyer Morrison, and the ship sank in eight minutes, with 154 casualties. A Baka bomb hit and fired the Shea, killing twenty-five and flooding the forward compartments, but the ship stayed afloat. A plane over the transports in the Hagushi area, after receiving fire from many ships, dived straight down into the Birmingham just aft of Number 2 turret. The impact carried the motor of the plane through three decks, and the 250-pound bomb burst in the sick bay. There were ninety casualties. More Japanese planes attacked at dusk. A suicide flyer hit the escort carrier Sangamon, destroying twenty-one planes on the flight deck. Her entire hangar deck was gutted by fire, and all radar and bridge control was knocked out. From the evening of 3 May until that of 4 May the Japanese had sunk or damaged 17 American ships and inflicted 682 naval casualties, while American planes and naval gunfire had destroyed 131 enemy planes. The enemy's air attack, which was simply one phase of his unceasing air campaign against the invading forces, amounted to 560 raids by 2,228 enemy planes between 1 April and 17 May and was probably the most profitable effort of his entire counteroffensive.{362}
General Amamiya refused to abandon the attack. Although both "spearheads" of his 24th Division had smashed vainly against the American defenses, suffering heavy losses in the process, he ordered another assault for the night of 4-5 May. The 1st Battalion, 32d Regiment, and the attached 26th Independent Infantry Battalion were directed to penetrate XXIV Corps lines northwest of Kochi in a night attack. The 1st Battalion had been used in support of the Japanese left "spearhead" on the 4th, but it had not been fully committed and was still relatively intact.
The reason for Amamiya's persistence after the morning's debacle is not clear, but one event of the day may well have led to his decision. Unknown to XXIV Corps, elements of the 1st Battalion, 22d Regiment, had penetrated more than 1,000 yards behind the American lines near Kochi. After dusk on the 4th these elements were ordered to pull back to their regimental lines. Amamiya may have reasoned that he had found a weak point in the American defenses. In any event the 1st Battalion of the 32d was given a similar route of approach, lying near the boundary between the 7th and 77th Divisions.{363}
The Japanese, having shelled the lines of the 306th Infantry during the night of 4-5 May, at 0200 launched an attack on the 306th where it straddled Route 5 northwest of Kochi. American artillery broke up this attempt. Three hours later the enemy attacked in battalion strength, supported by tanks. Although six tanks were soon knocked out, the Japanese pressed on through artillery and mortar fire to engage the 306th in close combat. They isolated a battalion observation post and killed or wounded its five occupants. Despite hostile heavy mortar fire, the Japanese set up knee mortars and heavy machine guns close to the American lines and even tried—unsuccessfully—to emplace a 75-mm. gun.{364}
Fierce fire fights developed along the regiment's entire line. One enemy force, moving up a draw in close column formation, marched squarely into a company and was destroyed by automatic weapons fire. Most of the Japanese, unable to close in for hand-to-hand fighting, took refuge in ditches just in front of the American positions. Grenade duels and exchanges of automatic fire continued until midday. By dawn, however, the 306th had the situation in hand. American tanks moved along the ditches and machine-gunned the enemy. Some of the surviving Japanese, using smoke for concealment, managed to withdraw to their lines. They left 248 dead in the 77th Division's sector, together with numerous machine guns, mortars, rifles, and several hundred rounds of 75-mm. ammunition for the gun they had failed to get into action.
TANABARU ESCARPMENT viewed from position of the 17th Infantry, 7th Division, on a finger of Hill 178. Company E, 17th, moved back to the secondary crest (right) on morning of 6 May after enemy had counterattack in force. Below appear the north and west sides of the escarpment, where Company F, 17th, regained the hill 7 May.