by moving the defending forces from the beaches along the northern shore and from around Changi, with the 18th Infantry Division being tasked to maintain control of the vital reservoirs and effecting a link up with Simmons' Southern Area forces. The withdrawing troops received harassing attacks all the way back. Elsewhere, the 22nd Brigade continued to hold a position west of the Holland Road until late in the evening when it was pulled back to Holland Village. On 13 February, Japanese engineers repaired the road over the causeway and more tanks were pushed across. With the Commonwealth still losing ground, senior officers advised Percival to surrender in the interest of minimising civilian casualties. Percival refused but tried to get authority from Wavell for greater discretion as to when resistance might cease. The Japanese captured the water reservoirs that supplied the town but did not cut off the supply. That day, military police executed Captain Patrick Heenan for espionage. An Air Liaison Officer with the British Indian Army, Heenan had been recruited by Japanese military intelligence and had used a radio to assist them in attacking Commonwealth airfields in northern Malaya. He had been arrested on 10 December and court-martialled in January. Heenan was shot at Keppel Harbour, on the southern side of Singapore and his body was thrown into the sea. The Australians occupied a perimeter of their own to the north-west around Tanglin Barracks, in which they maintained an all round defence as a precaution. To their right, the 18th Division, the 11th Indian Division and the 2nd Malaya Brigade held the perimeter from the edge of the Farrar Road east to Kallang, while to their left, the 44th Indian Brigade and the 1st Malaya Brigade held the perimeter from Buona Vista to Pasir Panjang. For the most part, there was limited fighting around the perimeter, except around Pasir Panjang Ridge, from Singapore Harbour, where the 1st Malaya Brigade—which consisted of a Malayan infantry battalion, two British infantry battalions and a force of Royal Engineers—fought a stubborn defensive action during the Battle of Pasir Panjang. The Japanese largely avoided attacking the Australian perimeter but in the northern area, the British 53rd Infantry Brigade was pushed back by a Japanese assault up the Thompson Road and had to fall back north of Braddell Road in the evening, joining the rest of the 18th Infantry Division in the line. They dug