Relatives of the miners wait at the site of the accident in Shuicheng County, southwest China's Guizhou Province, March 13, 2013. Twenty-one miners were killed and four others were missing in a coal and gas outburst Tuesday evening at Machang Coal Mine which belongs to Gemudi Company of Guizhou Water & Mining Group. Eighty-three miners were working underground when the accident took place, and 58 of them managed to get to the ground safely. (Xinhua/Ou Dongqu)