HUNTINGTON, Utah (AP) — Some noise was detected by two devices monitoring vibrations near where six miners were trapped by a cave-in nearly 10 days ago, raising ``a very small amount'' of hope that the men might be found alive, officials said.
The sound picked up by two geophones could be a rock breaking underground, or even an animal, said Richard Stickler, chief of the federal Mine Safety and Health Administration.
``We saw some indication of noise for a period of about five minutes that we had not seen before,'' Stickler said.
While the source of the noise wasn't known, Stickler said it had ``created a very small amount of hope and optimism'' among the families.
Rescuers were in the process of dropping a video camera and microphone down narrow holes being drilled into the mine, he said. Plans for a fourth borehole had changed because of the ``unusual'' readings.
Said Bob Murray, chief of Murray Energy Corp., the co-owner and operator of the Crandall Canyon Mine: ``Don't read too much into this noise we picked up, but it is a sign of hope.''
Still, experts say the chances of finding the men alive are slim.
As crews slowly dig a path to the men's presumed location at the Crandall Canyon Mine, the narrow drill holes sunk deep into the mountain amount to little more than educated guesses.
``There are a lot of possibilities,'' Stickler said. ``We started with logical thinking: 'If I were in this situation, what would I do?' That has guided us in where we look.''
The men could be huddled together or spread out anywhere in an underground area the size of several football fields.
``There's always a chance. You have to hang on to that chance. But realistically it is small, quite small,'' said J. Davitt McAteer, former head of the Mine Safety and Health Administration and now vice president of Wheeling Jesuit University in West Virginia. ``You would have to have every single break and divine intervention to successfully extract these guys.''
The Aug. 6 cave-in released low-oxygen air from sealed chambers into the working area of the mine. Downward pressure on the walls sent chunks of coal flying like bullets through the shaft.
Two holes drilled into the mine have not located the men. A third drill broke through Wednesday into an area where officials say the men may have sought refuge, but a microphone snagged in the hole about 20 feet above the roof of the mine, and it couldn't pick up any sound that might have come from below. Officials planned to lower a video camera with its own microphone in the next attempt.
``We're going to keep drilling until we find these miners,'' Murray said Wednesday.
Murray has acknowledged the drilling may not show whether the miners are alive or dead. At nearly every turn, he cautions reporters that the initial blast inside the mountain may have killed the men instantly.
Mining rescues after 10 or more days are not unheard of. In May 2006, two miners were rescued after being trapped for 14 days following a collapse at an Australian mine. In 1968, six miners were rescued after 10 days in West Virginia.
``I am still very optimistic that we will find these miners alive. There is real reason to believe that,'' Murray said Wednesday. ``I still remain very, very hopeful.''
The effort to dig out a rubble-filled tunnel was proceeding slowly Wednesday and could last another week to go more than 1,200 feet before reaching the area where the miners were believed to be working.
A ``seismic bump'' from the mountain settling damaged a coal excavator Tuesday night, stopping the advance for more than two hours, but work resumed after repairs were made to the 65-ton machine, Stickler said.
The miners ``know damn well we're doing what we can to get to them, and we're going to get there — no doubt about it,'' Bodee Allred, the mine's safety manager, said Wednesday in his coal-blackened overalls.
Allred, who has a cousin trapped inside the mine, said the force of the collapse was ``definitely something I've never seen before.''
The thunderous collapse blew out the walls of mine shafts, filling them with rubble. If the men were not crushed by rock, their bodies could have been crushed by the immense air pressure generated by the collapse, mining executives and federal regulators have said.
And if they survived that, they could have died from lack of oxygen, even though fresh air is now being pumped down one of the drill holes.
Mine officials believe the collapse released a ``rush of oxygen-depleted air'' into the area where the men were believed to be working, but officials are working on the theory that the bad air drove a pocket of breathable air into the back of the mine and that miners may have sought refuge there.
A blast of air came out of the mine's entrance, said Lane Adair, general manager of the Crandall Canyon Mine. For miners in the back of the mine, the blast would have felt like being inside an air compressor, he said.
Murray has said there are many reasons to have hope, citing video images showing about 5 feet of headroom deep inside the mine, with 2 or 3 feet of loose coal covering the floor.
The camera's light can reach only about 30 feet, but everywhere it points shows that the reinforced roofs of the tunnels appear intact, Murray said.
The voids could hold breathable air, although an initial sample showed barely 7 percent oxygen — not enough to support life.
The miners could find drinkable water seeping everywhere through the mine, although they would have little or no food, having probably consumed what food they brought with them for their 12-hour shift, officials have said.
The first hole was drilled 3.4 miles into the mine and more than 1,800 feet underground, where officials thought the miners may have tried to escape, only to find tunnels blocked. They dropped a microphone into that 2½-inch-wide hole, but picked up no sound.
A second hole about 8 inches wide was drilled to accommodate a camera. It was sent down near where the miners were known to be working at the time of the collapse but showed no miners — only a tool bag, a twisted conveyor belt, dripping water and pipes.
Union officials said Wednesday that their repeated offers to help at the nonunion mine were rejected immediately after the collapse. Mike Dalpiaz, international vice president of the union's District 22 in Price, said a union representative who offered ``anything and everything at our disposal'' was asked to leave the mine property.
Dalpiaz said he believes the aid was turned down because it meant letting union workers into a nonunion mine, though Murray said Tuesday the rescue effort couldn't accommodate any more people.
``We have all the manpower and equipment we can use in a confined space,'' Murray said. He added that his company was flying in a team of 14 managers as part of a second wave of relief.
The mine may have been made more dangerous by what Murray acknowledged was decades of digging using retreat mining, a common though sometimes dangerous method in which miners yank out a mine's pillars to grab the last of the coal.
Murray said the retreat mining took place before he took over the mine a year ago. He said no retreat mining was taking place at the time of the collapse, which he insists was triggered by an earthquake. Government seismologists say the mine's collapse registered as an earthquake.
``There's no connection between retreat mining and the natural disaster that occurred here,'' Murray said Tuesday. ``I've said that from the beginning, and that's the way it will eventually come out.''
Mine-safety experts say that two sections of the Crandall Canyon Mine that collapsed in March may have been an early warning sign. They questioned whether the company — and the government agency that oversees its work — should have closed the mine then.
Instead, operators moved to another section and continued mining.