Lightning forces teams out of W.Va. mine

NAOMA, W.Va.

Lightning has forced exploratory teams out of the West Virginia mine where 29 men died in the worst U.S. coal industry disaster in 40 years.

The federal Mine Safety and Health Administration says teams were withdrawn from Virginia-based Massey Energy Co.'s Upper Big Branch mine Monday afternoon. Teams left when lightning strikes were detected within 30 miles of the Raleigh County mine.

Regulators suspect a combination of methane gas and loose coal dust caused a deadly explosion at the mine April 5. The blast is the subject of civil and criminal investigations.

Teams have made repeated visits to the mine for nearly two weeks. They're making sure conditions are safe enough for investigators to work underground.