MELISSA BLOCK, host:
From NPR News, this is ALL THINGS CONSIDERED. I'm Melissa Block.
ROBERT SIEGEL, host:
I'm Robert Siegel.
And we begin this hour with a mystery. It is six weeks now since an explosion killed 29 miners in West Virginia, in one of the country's worst mine disasters, but no one knows what exactly caused the blast. Official investigations are just getting underway.
NPR has interviewed 10 men who worked at the coalmine, and most point to persistent problems with the flow of air.
BLOCK: This ventilation system is critical to prevent explosions, and most of the miners say it was troubled for months.
An NPR News investigation has also found that the FBI is looking into possible tampering with safety monitors that detect dangerous levels of methane. NPR's Frank Langfitt and Howard Berkes teamed up for this story, and we begin with Frank.
FRANK LANGFITT: After the massive blast in southern West Virginia, people who know coalmining were stunned.
Governor JOE MANCHIN (Democrat, West Virginia): Something went horribly wrong. I don't know how to repeat it more, but it went horribly wrong, and we've got to find out.
Mr. KEVIN STRICKLAND (Director, U.S. Mine Safety and Health Administration): Think about every major explosion, I've never seen anything of this magnitude.
Mr. STANLEY SUBOLESKI (Board Director, Massey Energy): If you had asked me before this occurred whether an accident of this magnitude was still possible in the U.S., I would have told you no.
LANGFITT: That was West Virginia Governor Joe Manchin, Kevin Strickland, head of coalmine safety for the federal government, and Stanley Suboleski, a director with the company that owns the mine, Massey Energy.
HOWARD BERKES: And this is Howard Berkes. The explosion stretched two miles underground. It was 10 times the size of the deadly blast at West Virginia's Sago Mine four years ago. Most people thought explosions this big were a thing of the past.
LANGFITT: Federal investigators think it was fueled by a buildup of methane and explosive coal dust. Methane gas is flammable, a natural feature underground. If it ignites and there's enough coal dust nearby, explosions follow.
For decades, mines have successfully used complex airflow plans to dilute methane with fresh air and disperse coal dust. At the Upper Big Branch mine though, miners say that plan was constantly changing in the months before the blast, and it never seemed to work.
BERKES: We spent the last several weeks talking with Upper Big Branch miners, most of whom still work for the mine's owner, Massey Energy. One former supervisor, a member of mine management himself said, quote, "They wouldn't fix the ventilation problems. I told them I needed more air. They threatened to fire me if I didn't run enough coal."
Another miner said of the airflow system: There was constant confusion. And a third miner said of management: They don't have a clue how to ventilate this place.
LANGFITT: Those miners and seven others we spoke with asked not to be named. They said Massey would fire them and they'd never get mining jobs anywhere else if their names were used. Then, we read their words to Stanley Suboleski, the Massey director. He said the mine always had more than enough air, and he was skeptical that managers would put production over safety.
Mr. SUBOLESKI: I would be just astounded that somebody would tell them to run coal without proper ventilation.
LANGFITT: Miners aren't the only people concerned about the mine's airflow system. Federal safety inspectors have been alarmed about airflow problems for months. In January, an inspector wrote a safety citation because air was flowing through part of the mine in the wrong direction.
BERKES: Miners questioned management about the problem. The inspector said the miners were told, quote, "Not to worry about it." Had there been an accident, he wrote, "Men would have died from smoke inhalation."
In early March, an inspector found air going the wrong way again. He sent the workers out of the mine for their safety and told the company to fix the ventilation system. The inspector called the incident one of high negligence.
LANGFITT: A Massey mine foreman told us plans for the airflow system became so mixed up they would have been comic if the stakes weren't so high.
Once, they gave the foreman a map with changes that needed to be made to the airflow system. He and his workers followed the instructions and built cinderblock walls to channel air safely through the mine.
On the next shift, the foreman said, management handed a completely different map to another crew, which promptly demolished the walls the first crew had just built.
The foreman said, quote, "Management didn't know what they were doing."
Massey Energy's Suboleski suggests this was miscommunication, not mismanagement.
Mr. SUBOLESKI: They may not have understood why some of these things took place. I guess I'm surprised that they weren't given a better explanation of what happened.
BERKES: What happened, Suboleski says, is that federal inspectors forced Massey to make changes to the airflow plan, changes, he says, Massey opposed but complied with anyway.
Suboleski has a doctorate in mining engineering from Penn State. He says the government-mandated changes actually decreased the flow of fresh air to a critical area before the blast.
Mr. SUBOLESKI: It was more complicated than it needed to be. In general, they made what ought to have been a fairly easy job more difficult. You know, we had what I'd call a professional disagreement.
LANGFITT: The ventilation plans are part of the FBI's criminal investigation, which we first learned about a few weeks ago.
I went to visit a miner. He came to the door, but said he couldn't talk because he was in the middle of an interview with an FBI agent.
When I went back later, the miner told me the agent asked these questions: Did a Massey manager make unauthorized ventilation changes? The agent also asked repeatedly if miners ever disabled methane monitors.
BERKES: The FBI is very interested in methane monitors because these devices warn miners and even shut down mining machines when methane approaches dangerous levels.
Two miners told the FBI they never saw anyone tamper with monitors. One said it would take a whole crew of idiots to do that. And some of the miners we spoke with said they'd heard of this dangerous practice in the mine, but none offered evidence it occurred.
A federal official told us that investigators, quote, "Will be looking very carefully to see if methane monitors were tampered with."
LANGFITT: But Massey Energy's Stanley Suboleski says he would be shocked if an employee disabled a monitor.
Mr. SUBOLESKI: The company would never condone an action like that. We would immediately fire anybody that - if we heard of an action like that occurring. It's just not tolerated in the company.
LANGFITT: Investigators also want to know whether the company kept accurate records of its methane readings. In fact, federal regulators told victims' families two weeks ago that they had discovered a methane record book with a page torn out and altered, according to two of the people present.
BERKES: Dangerous gases have kept investigators out of the mine so far, but it could be safe to go in next week, according to a federal mine safety official. When that happens, we're told the investigative teams will inspect the methane monitors, look for ignition sources, work to pinpoint the cause of the blast and try to figure out why it was so massive.
I hope they find out what went wrong, one miner told me, as he talked about the 29 buddies he lost in the mine.
Then, he quoted the safety signs he's seen every day of his long career underground: Accidents are caused, one sign says, they don't just happen.
I'm Howard Berkes.
LANGFITT: And I'm Frank Langfitt, NPR News.