The men who died from carbon monoxide poisoning at an eastern Kentucky coal mine were using the same air pack model as the Sago Mine disaster victims.
The lone Sago survivor questioned the reliability of the devices about a month ago, while the federal government has said they work when used properly.
Holly McCoy, spokeswoman for the Kentucky Office of Mine Safety and Licensing, said the self-contained self-rescuers, or SCSRs, used Saturday were the exact models the Sago miners were using: CSE SR-100. Miners commonly use that model.
Citing preliminary tests, a coroner said Sunday that three of the five Kentucky miners who died in a Harlan County mine Saturday survived the initial blast but succumbed to carbon monoxide. A sixth miner made it out alive.
David Dye, acting administrator of the U.S. Mine Safety and Health Administration, said in a statement Monday that the air pack of Kentucky's survivor had worked properly.
"Rescue workers who encountered the survivor during his escape independently corroborated that the survivor was using his SCSR when they encountered him," Dye said.
The federal agency said Monday that the explosion's cause remained under investigation. Investigators did not enter the mine Monday because the ventilation system was still being repaired, said Chuck Wolfe, spokesman for the state Environmental and Public Protection Cabinet. The team could head into the mine today.
Paris Thomas Jr., 35, Roy Middleton, 35, and George Petra, 49, died of carbon monoxide poisoning, the coroner said. Amon Brock, 51, and Jimmy D. Lee, 33, died of blunt force and heat injuries.
Jeff Ledford, whose brother Paul was the lone survivor, has disputed MSHA's assertion that his brother's air pack was working. He repeated Monday that his brother told him his SCSR worked for only five minutes. The devices are intended to supply up to an hour of air.
Randal McCloy Jr., the lone survivor of the Sago disaster that killed 12 miners in January, said in a letter to the victims' families last month that at least four of his crew's air packs had failed, forcing the men to share what little oxygen they had.
MSHA has said that air packs activated by the Sago miners worked properly. The agency has not said exactly how many air packs were activated, or how many it recovered.
During a hearing on the Sago disaster, an MSHA official testified that tests on the air packs showed none had been used to their full capacity before the trapped miners discarded them.
Scott Shearer, president of CSE, the Pennsylvania company that makes the air packs, was unavailable for comment Monday.
Kentucky legislators responding to the deadly accidents at mines across the country, including the Sago blast, passed a measure requiring mines to store breathing devices underground and to set up lifelines to help miners find their way out. But the law does not take effect until July.