MSHA investigators: Massey mine tragedy was preventable
A deadly explosion inside a West Virginia coal mine last year was preventable, officials with the federal Mine Safety and Health Administration said Wednesday.
Worn bits and a deficient spray system on a longwall shearer likely led to a small methane ignition that grew into a massive coal dust explosion inside Massey Energy Co.'s Upper Big Branch mine in Montcoal on April 5, MSHA Coal Administrator Kevin Stricklin said.
"The most likely source (of ignition) is the longwall shearer," Stricklin said. "Ignitions do occur. It's not a common thing; it's not something we like to see happen, but it does occur. Fortunately, in most situations there are other safety measures in place to keep that ignition from becoming an explosion."
Massey officials disputed what they called MSHA's "working theory."
"We do not currently believe that there were issues with the bits or the sprays on the shearer that contributed to the explosion," the company's general counsel, Shane Harvey, said in an e-mail. "We likewise do not believe that coal dust played a meaningful role in the explosion."
He said employees kept the coal dust under control with powdered limestone, a process known as "rock-dusting." Massey officials believe "that the mine exploded due to an infusion of high levels of natural gas."
Stricklin stressed MSHA's findings are not final and the investigation continues. The agency will conduct an internal review to see whether it could have better enforced regulations, he said.
In the months leading up to the explosion, federal investigators issued more closure orders for unsafe conditions at Upper Big Branch than at any mine in the country, MSHA officials said.
Mine operators are accountable, MSHA Director Joe Main said.
"They have a responsibility to be conducting investigations and examinations to protect their miners," Main said. "MSHA cannot be there all the time."
MSHA hopes to release a final report on the explosion in 60 to 90 days, Main said.
MSHA presented a "very viable scenario," said R. Larry Grayson, professor of energy and mineral engineering at Penn State University. If water sprayers were not working, they would not cool sparks created by frictional ignitions or dampen dust the shearer created, he said.
"When you wet the dust, it is then very unlikely to be involved in an explosion," Grayson said, noting that worn bits would not cut as cleanly as sharp bits and would generate more dust.
Based on investigators' findings so far, Stricklin painted a vivid image of the miners' last moments.
"There was an ignition, like a flame or burst of flame that would have gone on for anywhere from 70 to 90 seconds before it became a massive explosion," Stricklin said.
At least two miners apparently realized something was wrong and started running from the shearer, he said. They made it 400 to 500 feet.
"I would say they were moving as quickly as they could. ... I really don't know what they're thinking, I just know that they know they're in a bad situation and they're trying to get out," " Stricklin said.
The bits would have sparked if they had struck sandstone that surrounded the coal seam, Stricklin said.
The blast snaked two miles underground, twisted rails and destroyed machinery. It killed 29 miners, making it the deadliest U.S. mine disaster in 40 years.
It should not have happened, Stricklin said. With good airflow, a properly working water spray system, good dust control and vigilant operators willing to fix problems, such explosions will not occur, he said.
"From day one, we've always taken the position that all explosions are preventable, and we still stand by that today," Stricklin said. "If you follow all four of those things, we don't think an explosion would occur."
MSHA posted photos on its website of the shearer's severely worn-down bits. Investigators posted a "call out" order showing that mine operators reported no problems with the shearer 20 minutes before the explosion.
Had it worked properly, the spray system on the shearer would have helped extinguish an ignition and keep down dust levels, Stricklin said. More than 80 percent of samples taken from the mine show a high level of coal dust, which is highly flammable, he said.
Investigators interviewed 261 people, not including 18 potential witnesses who refused to testify, Stricklin said. Former Massey Chief Executive Officer Don Blankenship, who retired Dec. 31, was among those who refused to testify. Two Massey employees who entered the mine immediately after the blast and made their way toward the longwall also won't talk, Stricklin said.