of schedule. By 14 April, the division had swept all through the northern Ishikawa Isthmus, 55 miles from the original landings. The division's rapid advance continued until eventually they encountered prepared and dug-in defenders at Yae-Take, where the majority of the Udo Force was entrenched. The Udo Force, or Kunigami Detachment, under Colonel Takehiko Udo was built around the 2nd Infantry Unit of the 44th Independent Mixed Brigade—reinforced by having absorbed both former sea-raiding suicide squadrons and remnants of the Battalion earlier destroyed by the 6th—was responsible for defense of the Motobu Peninsula and Ie Shima. The 6th Division's drive captured most of northern Okinawa and the Division won praise for its fast campaign – Brigadier General Oliver P. Smith wrote: "The campaign in the north should dispel the belief held by some that Marines are beach-bound and are not capable of rapid movement." After heavy fighting in the south, the division was ordered to replace the Army 27th Infantry Division on the western flank. The 6th division advanced south to partake in the assault against the strong Japanese defense line, called the Shuri Line, that had been constructed across the southern coastline. The Shuri Line was located in hills that were honeycombed with caves and passages, and the Marines had to traverse the hills to cross the line. The division was ordered to capture the Sugar Loaf Hill Complex, 3 hills which formed the western anchor of the Shuri Line defense. The Marines that had assaulted the line were attacked by heavy Japanese mortar and artillery fire, which made it more difficult to secure the line. After a week of fighting, the hill had been taken. After Sugarloaf the Division advanced through Naha, conducted a shore-to-shore amphibious assault on, and subsequent 10-day battle to capture, the Oroku peninsula (defended by Admiral Ōta's forces), and partook in mop-up operations in the south. The battle on Okinawa ended on 21 June 1945. The Sixth division was credited with over 23,839 enemy soldiers killed or captured, and with helping to capture of the island, but at the cost of heavy casualties, including 576 casualties on one day (May 16) alone, a day described as the "bitterest" fighting of the Okinawa campaign where "the regiments had attacked with all the effort at their command and had been unsuccessful". For its actions at Okinawa, the 6th Marine Division (and reinforcing units) earned a Presidential