Federal inspectors fanned out across the coalfields over the weekend as part of a U.S. Mine Safety and Health Administration blitz aimed at underground coal operations with a history of ventilation, methane and coal dust violations.Teams of up to 10 MSHA inspectors targeted 57 mines in 10 states in a campaign directed by agency chief Joe Main under orders from President Barack Obama, in the wake of the April 5 explosion that killed 29 miners at Massey Energy's Upper Big Branch Mine in Raleigh County."The purpose of these inspections is to provide assurance that no imminent dangers, explosions, hazards or other serious health or safety conditions and practices are present at these mines," Main said in a prepared statement.MSHA did not immediately provide the results of any of the inspections.Twenty-three of the targeted mines were in West Virginia and another 14 in Kentucky. Eight of them were operated by subsidiaries of Massey, but other major coal producers were also on the list, including large unionized operations owned by CONSOL Energy and Patriot Coal.Meanwhile, investigations by state and federal officials into the Upper Big Branch disaster were getting started.On Wednesday evening, MSHA was scheduled to have its first meeting with the families of the fallen miners since the effort to recover any survivors ended late on the night of April 9. Representatives from the state Office of Miners' Health, Safety and Training and independent investigator Davitt McAteer were also scheduled to attend to explain the investigation process to the families.Despite promises from the Obama administration and Gov. Joe Manchin, no clear plan has yet been announced for providing any transparency or public access for the investigative interviews. Typically, such interviews occur behind closed doors, often with coal company lawyers allowed to attend.No interviews have taken place as of Wednesday evening, and the first interviews were scheduled to begin Tuesday, officials said."Final protocols have not been established," said Jama Jarrett, spokeswoman for state mine safety director Ron Wooten. "However, previous measures for other events taken by our office did not include open interviews for the public, press or families. In prior cases, transcripts were made public at the conclusion of the investigation."However, protocols and procedures could change as we move forward, given the fact that this investigation is entirely separate and unique from past events," Jarrett said.At least two widows from the Upper Big Branch disaster have asked MSHA to conduct its investigation through a formal public hearing, something MSHA has authority for, but has very seldom ever done. MSHA has not yet responded publicly to those requests.Also Thursday, Massey said it anticipates a loss of $80 million to $150 million related to the disaster for "benefits being provided to the families of the fallen miners, costs associated with the rescue and recovery efforts, insurance deductibles, possible legal and other contingencies."In addition, the company said the value of equipment and mineral rights potentially impacted by the disaster is about $62 million. "Massey will assess these assets for possible impairment once full access to the mine is restored, but it does expect to recover much of the equipment," the company said.Reach Ken Ward Jr. at email@example.com or 304-348-1702.