Rescuers search for survivors at the ruins of the Poly Explosives (Jinan) Co., Ltd., a professional manufacturer of civil explosive materials, after an explosion in Zhangqiu, east China's Shandong Province, May 20, 2013. Thirteen out of the thirty-four workers who had been pulled out of the rubble were confirmed dead in the accident that occurred Monday morning. [Photo/Chinanews.com]