ALLENTOWN - State regulators yesterday revoked the operating permit of a coal mine where a worker died in an explosion three months ago, alleging that a cover-up of a similar blast in 2004 might have contributed to the man's death.

The Department of Environmental Protection ordered R&D Coal Co. to seal its Buck Mountain Slope Mine in Tremont Township, Schuylkill County, and begin reclamation of the site. The order came after an investigation revealed similarities between the Oct. 23 blast that killed 43-year-old Dale Reightler and a 2004 accident at the mine that injured four workers.

"The owners and operators of this mine have been unwilling or unable to operate in compliance with state regulations, and have shown a disregard for the safety and well-being of the miners and their families," Jay Scott Roberts, deputy secretary for mineral resources management, said in a statement.

Reightler's death, from an explosion sparked by methane gas, was the first fatality in an underground Pennsylvania anthracite mine in more than eight years.

On Dec. 1, 2004, four workers at the mine were injured by what company officials said was flying debris and coal from an explosion caused by a pipe with a faulty gauge. R&D was allowed to reopen that month after installing safety equipment.

After Reightler's death, DEP investigators took another look at the 2004 case and found that the accident was caused by a methane explosion, not by debris from a ruptured pipe, and concluded that R&D officials had lied to state regulators.

If the DEP had known the truth in 2004, the agency might have been able to help the company remedy violations and prevent the blast that killed Reightler, the investigators wrote.

According to the report, released yesterday, "The cover-up of the previous accident and the similarities between the two accidents" indicate that the owners were unable or unwilling to operate the mine safely.

R&D officials did not return a phone message from the Associated Press.