MANY nations require their mines to contain underground safety chambers — airtight metal compartments with oxygen, water and food, providing a refuge for miners entombed by fires or explosions. Such chambers recently saved workers in a Canadian potash mine and a Tasmanian nickel mine.But America’s coal mines don’t have these lifesaving features. Why not?Disturbingly, reporter Ken Ward Jr. revealed Sunday that the 1969 U.S. mine safety law — passed after West Virginia’s 1968 Farmington disaster — espoused such chambers, but they never were required.The law authorized federal officials to mandate the refuges if an impending study by the National Academy of Engineering found them workable. A House committee report told the interior secretary “to promptly institute requirements for rescue chambers in mines if the study concludes such rescue chambers are indeed an effective method of insuring survival after a mine accident.”The academy study supported the refuges — but U.S. bureaucrats never acted. That’s outrageous. What went wrong? Did coal industry influence interfere? Reporter Ward repeatedly asked the federal Mine Safety and Health Administration for an explanation, but got no response. West Virginia’s members of Congress should demand public answers.After the Jan. 2 Sago mine explosion in Upshur County caused a dozen deaths, the Legislature overwhelmingly passed new mine safety requirements, and the state’s delegation in Washington introduced more federal reforms. But neither the state nor federal actions mentioned rescue chambers.Some experts disagree over effectiveness of the refuges in coal mines. Rob McGee of the U.S. Mine Rescue Association says coal fires and blasts are too violent for the chambers. But Larry Grayson, an engineering professor heading a rescue study for the National Mining Association, wrote in the St. Louis Post-Dispatch: “A portable refuge station, which is usually skid-mounted and kept close to the production area, could have saved the lives of the trapped miners at Sago.”This issue is too important to be left hanging. State and national leaders should act quickly to settle questions about effectiveness — then mandate the chambers in all coal mines, if the National Academy of Engineering conclusion remains intact, as we suspect it will be.The refuges are expensive, costing somewhere between $80,000 and $200,000. Coal mine owners probably will protest if they’re required. At the behest of Sen. Jay Rockefeller, D-W.Va., the U.S. Senate tentatively allowed owners to write off half the cost of safety investments, which would pass half the burden to taxpayers. But we hope the public isn’t stuck for too much of the expense that properly belongs to mine owners.Meanwhile, an immediate explanation is needed as to why federal officials never obeyed the 1969 directive for lifesaving chambers.