Updated

Trapped deep below ground by poisonous gases, the Sago miners realized at least four of their air packs did not work, and they were forced to share the devices as they desperately pounded away with a sledgehammer in hopes of getting rescuers' attention, the sole survivor says.

Finally, resigned to their fate, the men recited a "sinner's prayer," scrawled farewell notes to their loved ones, and succumbed, some as if drifting off to sleep.

"As my trapped co-workers lost consciousness one by one, the room grew still and I continued to sit and wait, unable to do much else," Randal McCloy Jr. wrote to his co-workers' families in a letter dated Wednesday and obtained by The Associated Press.

McCloy's two-page typed letter offered the most detailed account yet of what happened in the mine after the Jan. 2 explosion. The blast killed one miner and spread carbon monoxide that slowly asphyxiated 11 other men 260 feet below ground as they waited in the farthest reaches of the mine to be rescued.

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. But at least four of the devices did not function, McCloy said.

"There were not enough rescuers to go around," McCloy said. He said he shared his air pack with miner Jerry Groves, as co-workers did with the three other men whose devices were not functioning.

In a statement, mine owner International Coal Group Inc. said that the miners' air packs, also known as self-contained self-rescue devices, or SCSRs, were tested by federal investigators.

"ICG was informed that the SCSRs found at the barricade were deployed and showed evidence of use," the mine company said. "The federal investigators did not note any defective SCSRs and all appeared to be in working order."

After the blast, the miners returned to their shuttle car in hopes of escaping along the track, but had to abandon their efforts 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 the mine bolts and plates.

"We found a sledgehammer, and for a long time, we took turns pounding away," McCloy wrote. "We had to take off the rescuers in order to hammer as hard as we could. This effort caused us to breathe much harder. We never heard a responsive blast or shot from the surface."

Martin "Junior" Toler, 51, and Tom Anderson, 39, made another, last-ditch attempt to find a way out but were quickly 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.

McCloy said the air behind the curtain grew worse, and he lay as low as possible and tried to take shallow breaths, but became lightheaded.

"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. "The last person I remember speaking to was Jackie Weaver, who reassured me that if it was our time to go, then God's will would be fulfilled."

He said he has no idea much time went by before he passed out.

Groves' family members said Thursday they were grateful to McCloy, both for revealing details of Groves' final hours and for sharing his air pack.

"If they'd both had one that would work, they might have lasted a little longer," said Groves' mother, Wanda, who collapsed on Wednesday while reading McCloy's letter and was taken to the hospital with a minor stroke. She was released on Thursday.

Doctors have been unable to pinpoint why McCloy, 27, was the only who survived the 41 hours it took rescuers to find the crew. He left the mine battered and comatose and spent months in the hospital. He 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," he wrote. "I cannot explain why I was spared while the others perished. 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."

McCloy spokeswoman Aly Goodwin Gregg said Thursday that McCloy's letter was given to the families confidentially, and he would not comment further.

The Sago miners were using air packs manufactured by Monroeville, Pa.-based CSE Corp., according to the federal Mine Safety and Health Administration. The packs use a chemical reaction to produce oxygen. The company's literature says the units have a 10-year shelf life and require no maintenance beyond periodic visual inspections.

The SCSR contains a small window with a blue dot; if the blue dot is not present, then the SCSR is presumed to be ineffective and is discarded.

A call to CSE was not immediately returned Thursday.

ICG said in a statement that the SCSRs worn by the Sago miners "were all within the manufacturer suggested life," that the devices are checked every 90 days by a person at the mine, and are also checked by the wearer every day.

Production at the mine resumed March 15, and it was not immediately clear if ICG miners are now relying on the same type of devices.

At least two miners who escaped the blast said they, too, struggled with their air packs. Arnett Roger Perry told state and federal investigators he could not initially activate his.

"They're not worth a damn," co-worker Harley Joe Ryan, 60, told investigators. "There's going to have to be some design changes for them."

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.

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' family wants the government to adopt more flexible rules for conducting mine rescues. Rescue teams were not allowed to enter the Sago Mine until 11 hours after the blast because inspectors would not declare it safe.

"We know we need the coal," Wanda Groves said. "We're going to have to have mines. But we want them to be safe."