and by 1936 they were agreed that the Philippines should be written off. But in July 1941, this decision was abruptly reversed, and it became the policy of the U.S. government to defend and hold the Philippines. This was based, at least in part, in the belief that Boeing B-17 Flying Fortress bombers could deter or defeat an invading force. Soon after the Japanese invasion of the Philippines in 1941, MacArthur, in accordance with the pre-war plan, declared Manila an open city, and ordered his forces on Luzon to withdraw to Bataan. The Philippine government, the high commissioner's office and MacArthur's USAFFE headquarters moved to Corregidor Island. Although the dependents of U.S. military personnel had been sent back to the United States, MacArthur was, until his recall from retirement, a Philippine government employee, so his family had remained in the Philippines. MacArthur's wife, Jean MacArthur, and young son, Arthur MacArthur IV, went with him to Corregidor. Arthur celebrated his fourth birthday on Corregidor, on 21 February 1942. When an aide asked about Arthur's possible fate, MacArthur replied: "He is a soldier's son." Most of the United States Asiatic Fleet retired to the south of the Philippines. A small force was left behind under the command of Rear Admiral Francis W. Rockwell consisting of the submarine tender , the submarine rescue ship , gunboats , and , minesweepers , and , five tugboats, three small patrol boats, and the PT boats of Motor Torpedo Boat Squadron Three. The loss of Manila and the U.S. Naval Base Subic Bay meant that fuel and spare parts became scarce. The PT boats relied on Canopus and the floating dry dock for assistance with maintenance. Despite this, Motor Torpedo Boat Squadron Three continued to patrol. On 17 December, , and rescued 296 survivors from SS Corregidor, which had been carrying refugees to Australia when it struck a mine and sank in Manila Bay. A week later, ran aground while patrolling south of Manila Bay, and was set on fire to prevent her being salvaged by the Japanese. met a similar fate a month later, after its engines failed and it drifted onto a reef. The PT boats attacked enemy barges off Luzon on the night of 23 January 1942, a small Japanese warship on 1 February, and a small vessel, probably a fishing trawler, on 17 February. Decision Washington In a message to President Franklin