The decision had been made to invade the Philippines. Before doing so it was decided that it was important to capture Morotai and Peleliu to use as advance bases. Simultaneous landings were carried out on both islands on September 15, 1944. Morotai was swiftly captured with only symbolic Japanese resistance. Peleliu was another matter. The Japanese had concluded that resistance on the beaches was mostly futile. The overwhelming Amercian naval and air support easily overwhelmed any attempt to stop American forces at the beach. Instead they developed a strong line of defense including underground caves away from the beaches. Peleliu was the first place that defense was deployed.
The bombardment of the island had begun on September 12th, and the navy had time to clear all of the obstacle on the landing beaches. The First Marine Division veterans of Guadacanal were tasked with capturing the island. The Japanese despite having developed an in depth defense also tried to stop the landing. 210 Marines were killed and another 900 wounded on D-Day. The Marines captured the airfield on the 15th but the Japanese were too close to put it into use. The Marines were forced to attack each cave one at a time using a new weapon, a tank mounted flame thrower to defeat the Japanese. It was not until the night of the 24-25th that the last resistance was defeated and Japanese commander Colonel Nakagawa committed suicide.