CHARLESTON, W.Va. (AP) — More than 1,400 samples collected inside West Virginia's Upper Big Branch mine show excessive amounts of coal dust were present before an explosion killed 29 miners in April, a federal official said Friday.
A majority of the samples came from areas affected by the explosion, but show only that coal dust played a role in the blast, Mine Safety and Health Administration official Kevin Stricklin said during a conference call with reporters.
"It's going to be fair to say that coal dust played a role," Stricklin said. "We just aren't in a position to say how big of a role."
The findings bolster MSHA's preliminary findings issued 10 days after the explosion that a mix of methane and coal dust were responsible for the blast. Federal law requires coal mines to coat coal dust with pulverized stone or other inert material to prevent and contain explosions.
The explosion was the deadliest at a U.S. coal mine since 1970 and is now the subject of civil and criminal investigations.
Mine owner Massey Energy Co. criticized MSHA for releasing the test results.
"This is not the first time MSHA has attempted to use unproven or faulty coal dust claims in their investigation efforts," the Richmond, Va.-based company said in a statement.
MSHA contends that samples taken after an explosion contain less coal dust than they would have before a blast. "The explosion has had the opportunity to eat up or use up, burn up some of the combustible materials," Stricklin said.
Inspection logs filled out by Massey employees before the blast showed problems with coal dust as well.
The Associated Press reported Sunday that those handwritten logs showed eight of the mine's conveyer belts had excessive amounts of coal dust just 32 minutes before the explosion at 3:02 p.m. on April 5.
The logs, which Massey turned over to investigators, also show the mine routinely had to deal with excessive coal dust along the belts.
MSHA has collected 1,803 dust samples so far and 79 percent contained too little inert material to comply with the law, Stricklin said. Most of the samples came from parts of the mine affected by the explosion, with a minority taken just past the spot where seven of the victims were found.
Investigators still need samples from two areas that had been flooded in the 12-mile underground complex, Stricklin said. One of those areas is now drained, which will allow investigators to enter it and begin mapping, sampling and searching for clues. Stricklin expects pumping will begin shortly in the second area.
MSHA also is still searching for a methane detector that should have been at the mine's main working face and a remote control for the longwall mining machine used in that area. The agency also plans to recreate the mine's ventilation scheme as it would have been at the time of the blast.
"The majority of the underground work has been complete."
On the surface, investigators have conducted 235 interviews and plan about 20 more, Stricklin said. The agency is still considering whether it needs to interview Massey Chief Executive Don Blankenship.
Following the investigation, MSHA may cite Massey for violations that investigators determine contributed to the explosion and deaths. The agency also could fine the company. The criminal investigation is being handled separately by the U.S. Department of Justice.
MSHA's latest update came a day after Massey warned investors to brace for another quarterly loss, complaining that tougher enforcement was hurting productivity.
MSHA director Joe Main reacted quickly, saying mine operators are responsible for finding and fixing hazards instead of relying on government inspectors.
"When the industry comes to grips with this issue and figures out a way to beef up their health and safety programs, there's going to be less enforcement action for MSHA to take," Main said.