Rescuers queue to going into the shaft of the Beiyu Coal Mine where a roof collapse accident happened in Puxian County of Linfen City, north China's Shanxi Province, Feb. 19, 2012. Four workers were killed in the coal mine roof collapse accident. The accident occurred at about 1 p.m. Sunday, trapping seven workers who were working in the shaft. Rescuers are still searching for the remaining three. (Xinhua/Feng Ting)