were overrun near the Alangan River. The U.S. 45th Infantry Regiment (PS), under orders to reach Mariveles and evacuate to Corregidor, finally surrendered on April 10, 1942. Only 300 men of the U.S. 31st Infantry successfully reached Corregidor. Battle of Corregidor Corregidor (which included Fort Mills) was a U.S. Army Coast Artillery Corps position defending the entrance to Manila Bay, part of the Harbor Defenses of Manila and Subic Bays. It was armed by both older seacoast disappearing gun batteries of the 59th and 91st Coast Artillery Regiments (the latter a Philippine Scouts unit), an offshore mine field of approximately 35 groups of controlled mines, and an anti-aircraft unit, the 60th CA (AA). The latter was posted on the higher elevations of Corregidor and was able to respond successfully to the Japanese air attacks, downing many fighters and bombers. The older stationary batteries with fixed mortars and immense cannons, for defense from attack by sea, were easily put out of commission by Japanese bombers. The American soldiers and Filipino Scouts defended the small fortress until they had little left to wage a defense. Early in 1942, the Japanese air command installed oxygen in its bombers to fly higher than the range of the Corregidor anti-aircraft batteries, and after that time, heavier bombardment began. In December 1941, Philippines President Manuel L. Quezon, General MacArthur, other high-ranking military officers and diplomats and families escaped the bombardment of Manila and were housed in Corregidor's Malinta Tunnel. Prior to their arrival, Malinta's laterals had served as high command headquarters, hospital and storage of food and arms. In March 1942, several U.S. Navy submarines arrived on the north side of Corregidor. The Navy brought in mail, orders, and weaponry. They took away with them the high American and Filipino government officers, gold and silver and other important records. Those who were unable to escape by submarine were eventually military POWs of Japan or placed in civilian concentration camps in Manila and other locations. Corregidor was defended by 11,000 personnel, comprising the units mentioned above that were stationed on Corregidor, the U.S. 4th Marine Regiment, and U.S. Navy personnel deployed as infantry. Some were able to get to Corregidor from the Bataan Peninsula when the Japanese overwhelmed the units there. The Japanese began their final assault on Corregidor with an artillery barrage on May 1. On the night of May 5–6, two battalions of the Japanese