MSHA plans several staged public events later, but is conducting the key witness interviews in private. Despite the suit, interviews are scheduled to continue through the week. The private sessions are being held at the National Mine Health and Safety Academy outside Beckley.
"There are both public and private components to any law enforcement investigation," MSHA spokeswoman Amy Louviere said in a prepared response to questions. "Ultimately, this investigation will represent the most open process the agency has ever established."
Investigators believe, based on preliminary information, that the huge explosion was caused by the ignition of methane gas and probably made far worse by a buildup of highly explosive coal dust in the Upper Big Branch Mine.
The 29 deaths rank it as the worst U.S. coal-mining disaster in 40 years.
Also Monday, the U.S. House Labor Committee announced it would hold a field hearing on the disaster May 24 in Beckley. Family members of some of miners killed in the explosion at a Massey Energy mine in Raleigh County are expected to testify. The hearing will start at 9 a.m. at the Robert C. Byrd U.S. Courthouse.
Meanwhile, Massey and its CEO, Don Blankenship, continued their criticism of federal regulators, releasing a letter Blankenship sent to MSHA last week complaining that the agency had forced Massey to turn off nearly half of the air-cleaning scrubbers installed on its continuous mining machines in underground mines.
In response, MSHA issued a statement that said, "This is an issue we're looking at very closely. We plan to sit down with [the National Institute for Occupational Safety and Health] in the near future to discuss next steps."
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.