Workers celebrate the completion of the Yangtze River Tunnel in Shanghai, September 5, 2008. The world's widest tunnel with an inner diameter of 13.7 meters completed its excavation in Shanghai under the Yangtze River on Friday. The 8.9-km tunnel is part of a 12.6 billion yuan (US$1.84 billion) bridge and tunnel project to link Shanghai with Chongming Island, the country's third largest after Taiwan and Hainan. (Xinhua photo)