The backyard of a building collapses into an adjacent pit of a construction site after a cave-in accident in Xi'an city, capital of Northwest China's Shaanxi province, Sept 6, 2011, causing all 72 households in this building to be evacuated. The construction pit is just seven meters away from the building, according to the residents living in the building, but the contractors for the construction site claimed that the distance is 13 meters. An initial investigation indicated that the cave-in may have been triggered by rain lasting many days, and the loose soil, but the real cause cannot be confirmed before the results of the further investigation.[Photo/CFP]