Fifteen miners were killed after a poisonous gas leak caused an explosion at a modern state-owned coal mine in Henan province Friday night, state media reported. The provincial Coal Industry Bureau said 56 miners were underground at Malingshan coal mine in Dengfeng city when the explosion occurred. Owners Zhengzhou Coal Industry Group has US$795 million in assets and employs 45,000 workers. China produces about one-third of the world's coal but accounted for more than 80 percent of global coal mine deaths in 2004. The National Safety Administration reported last month that 5,986 had died in coal mine accidents in 2005.