By the early 20th century, many of the area's historic buildings were in serious decay. In 1900, bubonic plague broke out, and the state government resumed areas around The Rocks and Darling Harbour, with the intention of demolishing them and rebuilding them. More than 3,800 houses, buildings and wharves were inspected and hundreds demolished, but the continuation of these plans were brought to a halt due to the outbreak of World War I. During the 1920s, several hundred buildings were demolished during the construction of the Sydney Harbour Bridge.