I’ve seen it all before. First, the disaster, then the weeping and then the outrage. But in a few weeks, when the outrage is gone, when the ink on the editorials is dry, everything returns to business as usual.

— Sen. Robert C. Byrd, January 2006.

As expected, the politicians are out in force today, racing to proclaim their love for coal miners, though not always so much their love for taking the hard stands necessary to make mining safer. I’ve been trying to post most of the significant statements today, and we’ll have coverage later of tonight’s memorial service in Whitesville.

In the meantime, significant questions remain about what  happened on April 5, 2010 — and about what happened at Upper Big Branch in the weeks before then, not to mention what’s happened since. I thought I would try to give a rundown of what we know, what we don’t know and what we need to know. Here goes:

We know that Massey Energy’s Performance Coal Co. was having major safety problems. The company ran up hundreds of state and federal violations, with inspectors citing increasing concerns about the mine’s ventilation system in the months before it blew up.

We know that the men who worked there were concerned about their health and safety, but that they felt powerless to stand up for themselves, for fear that they would lose their jobs.

But we also know that MSHA did not use all of the tools at its disposal to bring this mine into compliance and protect the miners who worked there.

First of all, some bizarre computer glitch led MSHA to not warn Massey that the mine’s repeated citations constituted a potential pattern of violations, and that the agency — while not asking Congress for more money — hampered its own enforcement efforts under the Pattern of Violations provision of the Mine Act.

We also know that MSHA didn’t even try to use its long-standing legal authority to seek a court injunction that would have forced Massey to clean up the mine. Agency officials — and especially lawyers in the Labor Department solicitor’s office — waited until 29 miners got blown up to take that tool out of their toolbox.

And we know that MSHA didn’t try to use a newer tool, granted by Congress after a series of disasters in 2006, and fine Massey up to $220,000 for each and every “flagrant violation” of mine safety standards.

We also know that there are problems with the current safety law, weaknesses that could be cleared up by passage of the new law named after the late Sen. Robert C. Byrd.  We know that Republicans in Congress blocked this bill. But we also know that Democrats are pretty much refusing to press MSHA for answers — and reforms — to problems with the way the agency uses (or doesn’t use) the laws that are already on the books.

Rep. Nick Rahall, D-W.Va., talks to the media outside the Upper Big Branch Mine in April 2010. Gazette photo by Lawrence Pierce.

In this April 9, 2010 file photo, Travis McKinney is comforted by Cheyanne Graybeal as they view the casket of Travis’ grandfather, Benny Ray Willingham, at Mullens Pentecostal Holiness Church in Mullens, W.Va. Benny Ray Willingham was among those killed in an explosion at Massey Energy Co.’s Upper Big Branch mine. 29 coal miners were killed in the April 5 explosion. (AP Photo/Carolyn Kaster, File)

Beyond that, we also know that after every mine disaster, investigators inevitably find that MSHA missed things or didn’t do enough. And we know that internal agency audits in the months prior to Upper Big Branch found that the sorts of widespread problems MSHA has had for years continued.

More specifically, though, we don’t know how in the world MSHA could have allowed the kinds of conditions it described — widespread and serious violations of rock-dusting standards key among them — to exist at a mine that was supposed to be inspected more frequently than most because of its high methane liberation rate. (Not for nothing, but we also don’t know why MSHA has for years before the disaster ignored the need for tougher rock dusting standards, for better rock dust sampling procedures, and for more advanced dust meters and explosion-dampening devices).

We don’t know for sure what provided the spark that ignited the explosion, though MSHA and other investigators are looking closely at the mine’s longwall cutting machine, which had worn-out teeth and missing or inoperable water sprays that help minimize methane ignitions.

We don’t know what — if anything — either MSHA or Massey did after previous methane outbursts at Upper Big Branch in 2003 and 2004 to ensure that such incidents didn’t happen again, or cause a major accident. We don’t know if such an incident played a role in this disaster.  As with many of the things we don’ t know, we don’ t know this because the Obama administration has placed a higher priority on a criminal investigation of Massey Energy than on allowing the public, the families and the mining community have an open, transparent investigation that gives them trust and faith that those doing the investigating are really looking for the whole truth.

President Barack Obama, walks with Linda Davis, the grandmother of deceased miner Cory Davis, during a memorial for the victims of the Upper Branch Mine explosion at the Beckley-Raleigh County Convention Center in Beckley, W.Va., Sunday, April 25, 2010. (AP Photo/Steve Helber)

We know that U.S. Attorney Booth Goodwin has brought charges against two pretty low-level mine employees. We don’t know if Goodwin, the FBI and the Department of Justice will bring more charges against anyone — let alone against anyone in any real position of authority at Massey Energy.

We don’ t know if — as NPR’s Howard Berkes has repeatedly reported — workers at Upper Big Branch were disabling methane detectors or, if they did, whether that had anything to do with the disaster. We don’t know if federal prosecutors will hold any management people to account for such violations.

We aren’t sure exactly what kind of warning the Upper Big Branch miners working in the longwall section might have had that something was amiss in the moments before the disaster. And we don’t know — again, because MSHA won’t tell us — what changes that Massey had proposed or recently made in the Upper Big Branch underground ventilation system.  We don’t know if, as the Pittsburgh Post-Gazette has suggested, Massey’s use of air-lock doors instead of other ventilation controls might have played a role in the disaster.

We don’ t know for sure how many of the Upper Big Branch families will take Massey’s offer of a $3 million deal to settle potential wrongful death cases, or how many of the families will seek justice — and perhaps their own investigation of the disaster — through filing of such lawsuits.

We’ve learned in recent weeks and months that the mine rescue effort at Upper Big Branch wasn’t as much of a well-oiled machine as political leaders had us believe. But we don’t know for sure how bad it was, if any of the delays really made that much of a life-or-death difference (though we don’t believe so at this point), and we don’t know if MSHA is going to finally get serious about improving mine rescue response. But we’re still waiting to find out what tough-to-take details have been kept from the Upper Big Branch families.

We don’t know if there will ever be a full, public accounting of what led to this horrible disaster — the worst U.S. coal-mining disaster in nearly 40 years.

But the haunting thing remains what MSHA coal administrator Kevin Stricklin said a year ago, in one of those press briefings at Marsh Fork Elementary School:

All explosions are preventable. It’s just making sure you have things in place to keep one from occurring.