Mourners lay flowers for those killed by a deadly mudslide that occurred one year ago in Zhouqu county, Northwest China's Gansu province, Aug 8, 2011. [Photo/Xinhua]

People pay tribute in front of a monument for those killed by a deadly mudslide that occurred one year ago in Zhouqu county, Northwest China's Gansu province, Aug 8, 2011. [Photo/Xinhua]