The 13 miners trapped underground after a colliery gas burst in central China’s Henan Province were all confirmed dead on Tuesday night.Their bodies had all been found, according to China’s News Agency (Xinhua) reported.The outburst happened in a 500-meter-deep tunnel at a coal mine in Ruzhou City, where 16 miners were working underground. Three managed to escape.The coal mine belongs to the Changhong Mining Company Limited, an affiliated company of the state-owned China Pingmei Shenma Group.The cause of the accident is under investigation.