Little changed up until the Second World War, with the commercial success of the railway being closely linked to events in China. During the defence of Hong Kong in December 1941, various bridges and tunnels were deliberately blown up by the retreating British forces. After repairs had been made, the line was operated throughout the war by the Japanese using the services of the Chinese staff who had remained after the fall of the colony. During this period the railway gradually deteriorated through lack of adequate maintenance. Rolling stock and other equipment were also sent to China for use there by the Japanese.