The death toll from a coal mine gas leak in central China has risen to 30 after rescue workers discovered four more bodies. Report says, seven others remain trapped underground, but their chances of survival are slim. The gas leak occurred in Henan province when 276 miners were working underground. A total of 239 workers escaped. More than 2,500 metric tons of coal dust smothered the pit after the gas leak, hampering efforts to reach the miners.