Coal mines take several precautions to mitigate the two main causes of explosions: methane gas and coal dust. Methane can explode with the slightest spark if its concentration reaches 5 percent; coal dust is very combustible if too much accumulates.
SOURCE: Christopher Bise, chairman of the West Virginia University Department of Mining Engineering; West Virginia Geological and Economic Survey | Bonnie Berkowitz/The Washington Post - April 7, 2010
Even after 25 men die, 'we still have hope' Article | The first night, they prayed for a big miracle. The next day, people in the Coal River Valley were left hoping for a small one -- and wondering how many of the dead they knew. By evening, workers were drilling through a Swiss-cheese mountainside to reach four miners who might still be alive after th