When did they find that 13 people were dead in the accident?    

正确答案： B

解析： 新闻第二句提到Thirteen bodies were recovered…after the accident early Friday。由此可知尸体被发现是在星期五。
【录音原文】
　　The mayor of Chicafa, Albero Mecombo said Sunday that efforts to recover bodies at an open pit mine on the outskirts of the town will be suspended until Monday. Thirteen bodies were recovered during the initial rescue and recovery operation organized in the hours after the accident early Friday. Local residents worked until night fall, trying to save those buried. 3 people working in the 15-meter deep trench survived. No more survivors or bodies were found in rescue efforts on Saturday. But Mecombo said it is difficult to know how many people were working at the mine at the time of the accident. More victims, she said, might still be buried in the pit.