cipher room for coding and decoding messages, but by the time of the fall of Malaya, this work had been shifted elsewhere and the cipher room was used as sleeping quarters. The Commander of Fixed Defences, Brigadier Curtis, co-ordinated the coastal artillery strikes on naval targets from the bunker. World War Two By 1941, the bunker was considered to be too small for its intended use. Percival, having returned to Malaya as a lieutenant general and 'General Officer Commanding, Malaya', authorised construction of a new Combined Operations Headquarters at the Royal Air Force headquarters in Sime Road. The construction of this new headquarters began in 1941, and was finished in December of that year. Although Combined Operations Headquarters had been relocated to Sime Road, the Fort Canning Bunker remained the Headquarters of Major General Frank Keith Simmons, who as the 'Fortress Commander, Singapore', was responsible for the defence of Singapore Island. The Anti-Aircraft Gun Operations Room and Naval Extended Defences offices also remained at the bunker. The Japanese invaded Malaya on 8 December 1941 by moving south through Siam (now known as Thailand), as well as by making landings at Kota Baharu, on the north east coast of Malaya. Rapidly retreating through Malaya, Allied forces were forced back to Singapore Island by 31 January 1942. On 8 February, Japanese troops then crossed the Straits of Johor at the Battle of Sarimbun Beach on the north-west coast of Singapore Island, followed by a second landing near the Kranji River, at the Battle of Kranji. The Sime Road location had to be abandoned during the Battle of Kranji, with Lieutenant-General Percival shifting the Combined Operations Headquarters to Fort Canning Bunker on 11 February 1942. By the latter stages of the battle for Singapore, the Japanese were bombing the Central Area of Singapore, including Fort Canning Hill, at will. Fort Canning Hill was also within range of the Japanese artillery, forcing personnel into the bunker. There were around 500 officers and men in the bunker in the latter stages of the battle. The decision to surrender Singapore was made by Lieutenant-General Percival in a meeting on the morning of 15 February 1942. Held in the 'Commander, Anti-Aircraft Defence Room' of the bunker, a number of senior officers were in attendance, including Generals Bennett, Heath and Simmons. With diminishing water supplies, and no viable options for launching a counterattack, the decision was made to