Rescuers work at the accident site after a blast ripped through an explosives manufacturing plant owned by Poly Explosives (Jinan) Co., Ltd. in Caofan Township, Zhangqiu City, east China's Shandong Province, May 21, 2013. Thirteen people have been confirmed dead and 20 others remain missing after the explosion, which occurred on Monday morning inside a three-story terraced workshop of the plant. The explosion also injured 19 people. (Xinhua/Xu Suhui)