THE CONCLUSIONS of a state investigation into last year’s explosion of West Virginia’s Upper Big Branch coal mine were damning. The owner of the mine where 29 men died in the nation’s worst mining disaster in 40 years had, according to the report released in May, a pattern of negligence and a history of indifference to the safety of its workers. Now comes the even more devastating finding from federal investigators that the company conspired to hide safety problems. It is yet further evidence of why Congress must give government regulators the enforcement tools they need to better hold irresponsible operators accountable.

Officials from the Mine Safety and Health Administration (MSHA) held a briefing last week on results of its yearlong examination into the April 5, 2010, explosion. Some of it tracked the work of an independent team of West Virginia investigators who — detailing faulty equipment, shoddy safety practices and intimidation of workers who tried to report risks — concluded that the accident could have been prevented. But federal investigators went further with their determination that the company purposely misled government inspectors by keeping two sets of books — one that accurately accounted for hazardous safety conditions and another, the one shown to inspectors, that didn’t.

“If a coal mine wants to keep two sets of books, that’s their own business,” said Kevin Stricklin, MSHA administrator for coal. “What they have to do is record the hazards associated with the examination in the office record book, and that wasn’t the case here.” Falsifying records violates federal mining laws, and the findings have been referred to the Justice Department, which has already been investigating the case.

Massey Energy Co., which operated the mine at the time of the accident, has since been acquired by Alpha National Resources of Virginia. A spokesman for Alpha told us that the company is hearing this information at the same time it is being shared with the public and that it will investigate the claim about the two sets of records as part of its overall review of events at the mine in 2010. MSHA’s official report will be released in the fall, and the agency also has commissioned a separate review of its own actions before the explosion.

More, though, needs to be done to prevent future disasters, and it’s clear the current laws aren’t up to the job. Joseph Main, assistant labor secretary for mine safety and health, told a Senate committee on March 31 that additional tools were needed to deal with serial violators. These include stronger criminal and civil penalties, subpoena power to go after uncooperative operators, and whistleblower protections for workers who report hazards. Legislation sponsored by Sen. John D. Rockefeller IV (D-W.Va.) seems to be going nowhere, the victim of Republican opposition and an industry that fears the impact on profit and production. It’s hard to imagine a cost greater than the lives that have been lost.