Diggers use excavators and bulldozers to dig a diversion channel for a quake lake at Tangjiashan, Beichuan County on May 26, 2008. The lake was formed by landslides that blocked a river known as the Jianhe after the May 12 earthquake in Sichuan Province.Helicopters have airlifted professionals and materials for the operation to the area Monday afternoon. [Xinhua]