SCOTT SIMON, Host:
Howard Berkes has the latest in NPR's ongoing investigation of Massey Energy's Upper Big Branch mine. Howard, thanks so much for being with us.
HOWARD BERKES: Good to be with you.
SIMON: And what kind of safety systems are we talking about and why were they so critical?
BERKES: We're talking about water suppression systems, a fire suppression system that feeds the long wall mining machine in the Upper Big Branch mine that is believed to be the source of this explosion that took place there. This mining machine has a huge cutting tool called a shearer, and these water systems work to keep coal dust down as the shearer cuts into the coal. It works to keep sparks under control as the shearer sometimes hits rock, and it's there if a fire starts, and it's there also if there's some kind of small ignition that starts. These kinds of water systems can kind of keep that controlled and maybe even snuff it out.
SIMON: But there's a lot to suggest they weren't working properly before the explosion.
BERKES: And the bottom line on this is that the theory is that a small fireball, as I mentioned, was created by methane gas hitting sparks on this cutting tool. And so the idea is if all this stuff was working, you know, maybe it would've helped tamper that fireball, quench it, control it.
SIMON: But if they weren't working properly, it set in motion circumstances that could lead to an explosion.
BERKES: This huge explosion happened, went two miles through the mine. Twenty-nine miners were killed.
SIMON: Howard, what's the status of the criminal and civil cases against Massey Energy?
BERKES: And it's basically a wrongful death suit and it was filed by families of two of the victims of the Upper Big Branch explosion. And it cites these facts now in the amended complaint.
SIMON: And how close might investigators be to determining what really caused this terrible tragedy?
BERKES: There are strong indications that they have finished up the underground investigation; they have finished up more than 300 interviews - maybe have a few to go - and we think that perhaps by the first anniversary of this tragedy on April 5, we'll have some reports out that will give us a good sense of what happened. And the information that we've now reported is part of that good sense that they have of what might have taken place.
SIMON: NPR's Howard Berkes, thanks so much.
BERKES: Thank you, Scott.
SIMON: You can find an animated map illustrating possible causes of the Upper Big Branch explosion on our website, NPR.org.