A personnel carrier that once carried miners underground was left crushed and twisted by a 2006 explosion at the Kentucky Darby mine, which left five workers dead. Department of Labor/MSHA

Our friends at NPR News and the Mine Safety and Health News — Howard Berkes and Ellen Smith — have just posted some remarkable new work from a year-long investigation of what happens when coal mine operators never have to actually pay the safety fines that are assessed for violations of federal standards. Here’s how the web version of the NPR story starts:

Jack Blankenship was pinned facedown in the dirt, his neck, shoulder and back throbbing with pain.

He was alone on an errand, in a dark tunnel a mile underground at the Aracoma Alma coal mine in Logan County, W.Va., when a 300-pound slab of rock peeled away from the roof and slammed him to the ground. As his legs grew numb, he managed to free an arm and reach his radio. For two hours, he pressed the panic button that was supposed to bring help quickly.

“I couldn’t hardly breathe,” Blankenship remembered four years later. “I’d black out and come to. I was waiting to die. I’d already had my little talk with God.”

Aracoma Alma and then-owner Massey Energy had a history of serious safety problems, including falling rock. In the two years before Blankenship’s accident, the mine was cited by federal regulators more than 120 times for rock fall violations, according to records from federal regulators. That included inadequate roof support and deficient safety checks for loose rock.

The injuries Jack Blankenship sustained after a 300-pound rock pinned him to the ground while working in a coal mine, prevent him from sitting for long periods of time or walking far. He says he’s in constant pain. Anna Boiko-Weyrauch/NPR

Citations and the fines that go with them are key components of the federal law designed to protect miners. They are supposed to make violations expensive — costing hundreds of thousands of dollars for the most serious offenses — and create an incentive for mine owners to keep workers safe.

Yet on that December day in 2010, as Blankenship lay pinned and in pain, Aracoma Alma owed $200,000 in overdue mine safety fines, federal records show. The penalty system that is designed to discourage unsafe practices failed Blankenship, and his story is not unique.

And the nut graph:

A joint investigation by NPR and Mine Safety and Health News found that thousands of mine operators fail to pay safety penalties, even as they continue to manage dangerous — and sometimes deadly — mining operations. Most unpaid penalties are between two and 10 years overdue; some go back two decades. And federal regulators seem unable or unwilling to make mine owners pay.

Our joint investigation looked at 20 years of federal mine data through the first quarter of 2014, including details about fines, payments, violations and injuries. We used raw Department of Labor data and delinquency records provided by the Mine Safety and Health Administration to calculate the number of injuries and injury rates, and violations and gravity of violations, at mines with delinquent penalties while they were delinquent.

The first of the radio stories is set to begin in a bit on All Things Considered (available via West Virginia Public Radio) and more stories are planned Thursday and Friday.