 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.