The Canadians were initially positioned on the south side of the Island to counter any amphibious landing. This meant that when the Japanese invaded the island they were the units called upon to counterattack. On 8 December, Japanese aircraft destroyed a nearly empty camp at Sham Shui Po where two men of the Royal Canadian Signals were wounded, the first Canadian casualties in the Pacific theatre, and the first Canadian army casualties in combat. On 11 December, the Winnipeg Grenadiers became the first Canadian Army subunit to fight in battle in the Second World War, with D Company acting as a rearguard during the retreat from Kowloon. Private John Grey was killed during the evacuation. It is unknown how he died but guesses have included mobs, fifth columnists, and being executed by the Japanese. The majority of the men of C Force were strongly patriotic and saw themselves as fighting for the British empire, and in particular believed that by defending Hong Kong that they were defending Australia, seen at the time as a fellow member of the Commonwealth "family". The Japanese had believed that after smashing through the Gin Drinkers' Line that the British would surrender Hong Kong and that the operation would last only three days at most. Maltby had expected the Gin Drinkers' Line to hold for a least a week, and was shocked that the Japanese had broken through so quickly over the course of one night. One of Maltby's staff officers later remembered the headquarters was in "chaos" with no one really knowing what was happening or what to do. Maltby ordered Lawson to sent the Winnipeg Grenadiers to Kowloon.