Chief of Coast Artillery Major General Joseph A. Green had recommended reassigning elements of the Harbor Defenses to anti-aircraft duty, but this proposal was rejected. However, a few harbor defense batteries manned AA batteries in the campaign. Most of the AA batteries at the harbor forts were manned by the 60th Coast Artillery (AA). The War Department had been intending to send three additional AA regiments and two brigade headquarters, however only one was sent before the Japanese invasion in December 1941. This was the 200th Coast Artillery (AA), which arrived in September 1941 and initially defended Fort Stotsenburg and Clark Field. The 515th Coast Artillery (AA) was formed in December 1941 using stored AA weapons and troops detached from the 200th, soon augmented by Philippine Army personnel. The regiment initially defended Manila. However, after Manila was declared an open city on 26 December, the 200th and 515th screened the withdrawal to Bataan and fought in the Battle of Bataan. When US forces in Bataan surrendered on 9 April 1942, these units were forced to join the Bataan Death March. With the exception of those areas covered by the 60th, 200th, and 515th CA AA regiments, the Philippine islands were virtually defenseless against air attack.