Updated

Federal regulators are scrambling to reassure the nation's 42,000 coal miners that the air packs they rely on in an emergency will work, even though the sole survivor of the Sago Mine disaster says four of his crew's devices malfunctioned.

Congressmen and some of the Sago victims' relatives, meanwhile, are calling on government to upgrade air packs and require the use of tracking devices and communication systems to make sure West Virginia's heartache is never repeated.

"We know we need the coal," said Wanda Groves, whose son Jerry Groves was among the 12 who died at Sago. "We're going to have to have mines. But we want them to be safe."

The revelation about malfunctioning air packs came from Sago survivor Randal McCloy Jr. in a letter delivered to his co-workers' families and obtained by The Associated Press.

The air packs — referred to in the letter as "rescuers" — are intended to give each miner about an hour's worth of oxygen while they escape or find a pocket of clean air. McCloy said at least four of the devices did not function, forcing the trapped men to share as they awaited a rescue that came too late.

"His heart-wrenching account of the last hours of his co-workers' lives should spur this Congress to act on our legislation," said Rep. Nick Rahall, D-W.Va.

Rep. George Miller, D-Calif., noted that Congress needed only 40 days to pass a bill after Janet Jackson's wardrobe malfunction at the Super Bowl.

"It's been almost four months since the Sago mine disaster and there has been no action," he said.

Mine owner International Coal Group Inc. said federal investigators tested the miners' air packs — also known as self-contained self-rescue devices, or SCSRs — and found no evidence any of them malfunctioned.

Dirk Fillpot, spokesman with the Mine Safety and Health Administration, confirmed that the agency and the National Institute for Occupational Safety and Health examined all the air packs recovered from the mine.

Initial tests found that the devices that had been activated would have functioned properly, he said. However, MSHA will look into whether the Sago miners had been adequately trained to use them, he said.

The Jan. 2 blast killed one miner, then spread carbon monoxide that slowly asphyxiated 11 other men 260 feet below ground.

The miners returned to their rail car in hopes of escaping along the track, but had to abandon the effort because of bad air. They then retreated, hung a curtain to keep out the poisonous gases and tried to signal their location by beating on roof bolts and plates.

Martin "Junior" Toler, 51, and Tom Anderson, 39, tried to find a way out but were turned back by heavy smoke and fumes, McCloy said.

"We were worried and afraid, but we began to accept our fate," he wrote. "Junior Toler led us all in the Sinners Prayer" — a prayer for salvation of one's soul.

"Some drifted off into what appeared to be a deep sleep, and one person sitting near me collapsed and fell off his bucket, not moving. It was clear that there was nothing I could do to help him," McCloy wrote.

Groves' family members said they were grateful to McCloy, both for revealing details of the miners' final hours and for sharing his air pack. But Jerry Groves' brother, John, said it was difficult to learn the news that some of the air packs hadn't worked.

"That's the part that really angers us and really hit home for me — whenever I see the part where they sacrificed their oxygen for their brothers ... to live," he told ABC's "Good Morning America" Friday.

Doctors have been unable to pinpoint why McCloy, 27, was the only miner to survive the 41 hours it took rescuers to find the crew, though they have said his youth may have helped. He was hospitalized for several weeks in a coma and suffered brain damage that affects his ability to hold a conversation.

"I cannot begin to express my sorrow for my lost friends and my sympathy for those they left behind," McCloy wrote. "I hope that my words will offer some solace to the miners' families and friends who have endured what no one should ever have to endure."

Though state and federal investigators have reached no official conclusions about the cause of the explosion, ICG officials say they believe it was caused by a lightning bolt that ignited a buildup of naturally occurring methane.

McCloy's letter said that three weeks before the blast, he and Toler found a pocket of methane gas. After reporting it to supervisors, they discovered it had been plugged with glue normally used to secure roof bolts and layers of rock.

International Coal Group said the SCSRs worn by the Sago miners "were all within the manufacturer suggested life," the devices are checked every 90 days by a person at the mine and are checked by the wearer every day.

The Bush administration is reviewing air packs and other safety equipment used in the nation's mines after previously scrapping similar initiatives started by the Clinton administration.

Groves' relatives want the government to adopt more flexible rules for mine rescues. Teams were not allowed to enter Sago until 11 hours after the blast because inspectors would not declare it safe.

"If we have to get on a bus to Washington, D.C., to make sure these changes are made," said his brother John Groves, "then that's what we need to do."