CHARLESTON, W.Va. -- Federal investigators will conduct key portions of their probe of the Upper Big Banch Mine disaster behind closed doors, but will plan a series of public events the Obama administration said would "bolster transparency and openness."The announcement Thursday by Labor Secretary Hilda Solis drew harsh criticism from the United Mine Workers union, mine owner Massey Energy and families of miners killed in the April 5 explosion."People from all sides of this issue in the coalfields want this investigation to be fully and completely open," said UMW President Cecil Roberts. "The families of the victims do, the UMW does, the media does, and even the company said it does."The only people who don't want this to be completely open are the government agencies, and that, frankly, continues a bad practice that we expected would change under this administration," Roberts said.Massey said the U.S. Mine Safety and Health Administration "is choosing to repeat past mistakes by refusing due process and failing to build the public's confidence that the hearings will be fair and develop a complete and balanced public record."Federal law gives MSHA authority to conduct accident investigations through public hearings, but the agency has seldom done so.The UMW, Massey, at least two miners' widows and a coalition of media organizations, including The Charleston Gazette, had called for MSHA to hold the witness interviews in a public hearing.Solis rejected those requests, saying the interviews would be private with transcripts being released later unless those being questioned asked for confidentiality or MSHA believed the release would harm ongoing criminal investigations.Later, MSHA plans to hold a public hearing where mine officials, miners and others would testify. The agency also plans a second, more technical hearing to examine theories of what caused the explosion.Also, MSHA said it would hold a public forum where families could speak out, a public comment period, and a "town hall meeting designed to promote the exchange of ideas on how best to create a culture of safety at mining operations, and to gather recommendations on how to improve mine safety moving forward.""This approach is being driven by a commitment to learn what caused the explosion that claimed 29 miners' lives, a commitment to transparency and openness, and a commitment to ensure that MSHA's investigation does not impede any potential or ongoing criminal investigations into the blast," said MSHA chief Joe Main, a former UMW safety director.Tony Oppegard, a longtime mine safety advocate, said he was very disappointed in the agency's plan for the Upper Big Branch investigation."They can call them public hearings, but a public hearing is only when the investigation is all in the public," Oppegard said. "It's not a public hearing to do it later, after all the interviews are over."The MSHA plan apparently will prohibit the UMW -- which was appointed as the "miners representative" by several workers at the nonunion Upper Big Branch -- from taking part in the interviews. And, the plan also will prohibit families of the miners killed or lawyers for those families from sitting in on the interviews.But Tim Bailey, a lawyer for the family of fallen miner Adam Morgan, said the MSHA plan will allow Massey lawyers into the interviews if the company persuades mine officials and miners to let them act as their "personal representative" during questioning."If they are going to exclude the miners' representatives, they ought to exclude the company representatives, too," Bailey said.But a Labor Department spokesman, Carl Fillichio, said the agency plan prohibits Massey lawyers from getting into interview sessions by persuading nonmanagement workers to designate them as their "personal representatives" for the questioning.Massey lawyers could in most circumstances attend interviews with management employees. A detailed MSHA document released Thursday night would allow company lawyers to represent nonmanagement employees in some situations, but also said Massey has said that will not occur.Reach Ken Ward Jr. at firstname.lastname@example.org or 304-348-1702.