Luzon - 1944-1945 - CMH Online Shimbu Group - General Yokoyama - The Pacific War Online Encyclopedia: Yokoyama Shizuo "The battles for Manila, Bataan, and Corregidor were only the beginning of the Luzon Campaign. Both Shobu Group, securing northern Luzon, and the bulk of Shimbu Group, defending the south, remained intact. With about 50,000 men at his disposal, the Shimbu Group commander, General Yokoyama, had deployed some 30,000 of them immediately east and south of Manila, with the remainder arrayed along the narrow Bicol Peninsula to the southwest. The main Japanese defenses near the capital were built around the 8th and 105th Divisions, with the rest of the manpower drawn from a jumble of other units and provisional organizations. East of Manila, their positions were organized in considerable depth but lacked good lines of supply and reinforcement. Shimbu Group's eastern defenses obviously presented the most immediate threat to American control of the Manila area and would have to be dealt with first. By mid-February Krueger's Sixth Army staff had begun planning operations against those Shimbu Group forces closest to Manila. Although still concerned about Shobu Group troop concentrations in northern Luzon, both Krueger and MacArthur agreed that the Manila area, the potential logistical base for all American activities on Luzon, still had first priority. Nevertheless, MacArthur made Krueger's task more difficult in the coming weeks by continually detaching troop units from Sixth Army control and sending them to the southern and central Philippines, which had been bypassed earlier. These diversions greatly impaired Krueger's ability to deal with both Shobu and Shimbu Groups at the same time." Antipolo "Men of the 122d Field Artillery Battalion, 33d Division, fire a105-mm. howitzer against a Japanese pocket in the hills ofLuzon. (National Archives) By 20 February Krueger had positioned the 6th and 43d Infantry Divisions, the 1st Cavalry Division, and the 112th Cavalry Regimental Combat Team for an offensive in the rolling hills east of Manila. In addition, as soon as Manila was secured, he wanted the 11th Airborne Division to clear the area south of the capital, assisted by the independent 158th Infantry. He hoped that the first effort could begin immediately and that the second would start by the first week in March. On the afternoon of 20 February the XIV Corps launched its attack. Griswold assigned the 6th Division the task of capturing the dams in the north and ordered the 2d Cavalry Brigade, 1st Cavalry Division, to attack the southern half of the Japanese defenses and secure the town of Antipolo. Both units traversed the broad Marikina Valley unmolested but encountered fierce resistance as they moved into the hills and mountains forming the valley's eastern wall. There the Japanese had honeycombed the area with subterranean strongholds and machine gun positions covering all avenues of approach. Despite massive Allied air support, the cavalry advanced slowly, on some days measuring progress in mere yards: Not until 4 March did the troops reach Antipolo. But success was bittersweet. The brigade had lost nearly 60 men killed and 315 wounded, among them the 1st Cavalry Division commander, General Mudge. Verne Donald Mudge (1898 - 1957) - Find A Grave Memorial To the north the 6th Infantry Division fared only slightly better. Its initial objectives were Mount Pacawagan and Mount Mataba, two strategic high points crucial to capturing the Wawa Dam. Both mountains were defended by extensive Japanese artillery and infantry positions. By 4 March the infantry's southernmost elements had gained a precarious foothold on the crest of Mount Pacawagan, but they could go no farther. Just to the north the Japanese continued to deny the Americans any gains in the Mount Mataba area. Not until 8 March did the infantry regain its momentum, gouging the Japanese defenders from their positions as they advanced. PFC Jeston C. Whittington(ASN: 34596505), United States Army, 1st Cavalry Division, 82nd FAB Batt.A PFC Cozby L. Curnutt (ASN-38477843) 1st Cavalry Div., 8th Cavalry Regt. KIA Antipolo March 2, 1945 PFC Ruben Corona (ASN-39136948) 1st Cavalry, 8th Cav Regt. KIA Antipolo, March 8, 1945 PFC Arthur J. Howell (ASN-34448649 ) 1st Cavalry, 7th Cavalry Regt. KIA Antipolo March 11,1945 PVT Ace Hartman (ASN-39477784) 1st Cavalry, 7th Cav. Regt, KIA March 11,1945 Antipolo PFC John R Brown (ASN-17048349) 1st Cav Div. 12th Cav Regt. KIA-Anitpolo March 9, 1945 PFC William J. GRABIARZ (No NARA ASN-Not Needed) Troop E, 5th Cavalry, 1st Cavalry Division. M.O.H. SGT Joseph J. Bentz (ASN-32568939) 1st Cav. Div., 7th Cav. Reg. KIA-Antipolo-March 11, 1945. PVT Willie D Tyler - 1st Cavalry Div, 7th Cav. Reg. KIA Antipolo March 10, 1945 SGT Roberto S. Garcia (ASN: 18022756), US Army, 12th Cavalry Regt, 1st Cavalry Division JAPS SEALED IN CAVES ON LUZON BY THOUSANDS (March 10, 1945) From his vantage point in the mountains, General Yokoyama was concerned by these advances that threatened to envelop both his flanks. Unwilling to abandon his excellent defensive positions on Mataba and Pacawagan, he decided instead to launch a counterattack aimed at the advancing 6th Division. His plans and their subsequent execution typified major Japanese tactical weaknesses throughout the war. Yokoyama scheduled a series of complicated maneuvers that required meticulous coordination in difficult terrain, necessitating sophisticated communications that Shimbu Group lacked. In addition, the Japanese artillery was neither strong enough nor suitably deployed to provide proper support. Still, the counterattack began on 12 March with three reserve battalions assaulting three widely dispersed positions along the American line. How Yokoyama expected these scattered attacks to succeed is unclear, but to make matters worse, they ran straight into another major offensive of the 6th Division. In fact, the counterattacks were so weak that the Americans had no idea they were even under attack. The entire effort demonstrated only that Shimbu Group was incapable of effective offensive action and that the original defensive strategy was the best course. But the Japanese were irretrievably weakened by the failed counterattack, and to Yokoyama the ultimate fate of Shimbu Group was a foregone conclusion. All he could do now was trade lives for terrain and time. For the next two days, 13-14 March, the Americans battered through Japanese positions, bolstered in the south by a regiment of the 43dDivision sent in as reserve for the 1st Cavalry Division. The 6th Division successfully cleaned out the extreme northern Japanese positions, securing a strong foothold on Mount Mataba. The cost, however, continued to be high. On the morning of 14 March a burst from a hidden Japanese machine gun position caught a group of officers bunched together at a regimental forward command post, mortally wounding the division commander, Maj. Gen Edwin D. Patrick (1894 - 1945) - Find A Grave Memorial, and one of the regimental commanders. Still, the dual offensives had begun to cave in the Japanese defensive line at both the northern and southern flanks, killing an estimated 3,350 enemy troops. On the American side, the XIV Corps lost almost 300 dead and over 1,000 wounded in less than a month of fighting. On 14 March General Hall's XI Corps took over responsibility for operations against Shimbu Group. With the 38th and 43d Infantry Divisions, Hall decided to continue XIV Corps' strategy, although he intended to concentrate more heavily on destroying the Japanese left,"