求翻译：　　据指挥部11日23时40分介绍，事故发生后，尽管指挥部对井下工作人员数量进行了认真统计，但还是没有核准。后经进一步核查，事故发生时井下作业人员为31人，7人成功升井，24人被困。是什么意思？

　　According to command 11th introduction, after the accident, although underground staff headquarters to be a serious statistics, but it is not approved. After further verification, underground work personnel of 31 people when the accident occurred, 7 were successful rise well, 24 people were trapped.