As claimed by the state media, a Chinese mine where 21 workers were killed on Thursday and 22 more remain trapped was being operated illegally as a year ago, it lost its license. The government of China is trying to shut down illegal mines from long time as a measure to improve the industry’s terrible safety record. And due to this measure by the government, the official death rates in the mines has come down from a high of about 7,000 in 2002 to about 2,600 in 2009. A huge rescue operation is still going on at the mine. Investigators believe a sudden release of gas into the pit trapped the miners. But there’s a conflict whether it was an explosion or a leak. However no survivors have been found as of now.