A mine explosion killed at least 25 miners Monday in West Virginia, reports Yahoo News.  The search still continued on Tuesday for four missing miners.

Crews are creating an access road in order to drill access holes into the ground to access the trapped miners.  The crews were battling poisonous gas from the mine.  It may not be until Wednesday night until the first access hole is drilled.

Witnesses said that they knew something was wrong when the carbon monoxide alarms started to go off.  After checking the alarms, the workers discovered the explosion.

There were 31 miners in the area when the explosion occurred.  Some of the 25 who died may have died from the breathing in the toxic carbon monoxide gas.