A federal report says an abandoned pump cable deep inside the Sago Mine was the likely conduit for lightning that touched off a methane explosion.
Twelve coal miners died in the January 2006 disaster, one from the initial blast and eleven others from carbon monoxide poisoning during a long entrapment deep inside the underground Upshur County mine.
An early copy of the Mine Safety and Health Administration report, obtained by The Associated Press, says lightning was one of three "root causes."
Previous reports by the state and mine owner International Coal Group also blamed lightning, but this is the first time a conduit for the electrical charge has been mentioned. A report by the United Mine Workers suggested the spark came from roof friction.
MSHA's report says two simultaneous lightning bolts likely created an electrical arc that traveled along the abandoned and damaged cable.
The report also says gas levels inside the sealed section of the mine where the explosion occurred were not monitored and that seals used to close off that section were not strong enough to withstand the blast.
Thirty-two violations were issued against ICG, but none were found to have caused the accident or contributed to its severity.
A spokesman for the Scott Depot-based company declined comment,
saying he hadn't seen the report.
(Copyright 2007 by The Associated Press. All Rights Reserved.)