The aerial photo taken on May 28, 2008 shows the working site of the Tangjiashan quake lake near Beichuan County in southwest China's Sichuan Province. The earthquake-induced lake is at risk of bursting and threatening thousands of people downstream. Some 30 excavators are working non-stop to dig a diversion channel to drain the lake, which is expected to be completed within 5 to 7 days if weather permits. A large number of residents in Mianyang City are prepared to be evacuated from their homes. (Xinhua/Li Gang)

A Mig-26 helicopter is about to carry a bulldozer to the Tangjiashan quake-induced lake near Beichuan County in southwest China's Sichuan Province, May 28, 2008. The earthquake-induced lake is at risk of bursting and threatens thousands of people downstream. Some 30 excavators are working non-stop to dig a diversion channel to drain the lake, which is expected to complete within 5 to 7 days if weather permits. A large number of residents in Mianyang City are prepared to evacuate.(Xinhua/Li Gang)