Third rescue attempt at West Virginia mine delayed until Thursday evening

A third rescue attempt won’t be made until at least Thursday evening at the Upper Big Branch mine, where a buildup of poisonous and explosive gases prevented crews from reaching four missing miners who may be housed in refuge chambers after a devastating explosion killed 25 coworkers Monday.

Emergency crews have completed drilling a second borehole intended to double the rate of ventilation of the deadly air. Rescue workers won’t be sent back into the mine until methane and carbon monoxide concentrations drop to safe levels, a process expected to take until at least 6 p.m. EDT, and possibly much later.

A third hole, aimed at one of the rescue chambers, is being drilled to allow workers to lower a camera into the mine to determine whether the chamber has been entered. That process might not be completed until after midnight, according to emergency officials.

J. Christopher Adkins, chief operating officer of Massey Energy Co., told reporters that crews had entered the mine Thursday morning but were forced to turn around when a change in barometric pressure due to weather raised the concentration of highly explosive methane in the mine.

“The barometer dropped and we started seeing the methane pick up in the borehole that we’ve got drilled down there . . . to detect the air,” Adkins said. “We immediately called underground and had our mine rescue teams withdraw.”

Because methane is absorbed onto the surface of coal, a decrease in atmospheric pressure means that more methane is released into a mine atmosphere, according to Christopher Bise, a mining engineer at West Virginia University. The effect is much like reducing the pressure in a soda bottle, which will pull carbon dioxide out of the soda.

“It’s something we’re used to,” Adkins said. “It’s common in the mining industry. The barometric pressure will go to a certain point and then stop, and then it drops.”

When rescue crews are able to go back in, they may be able to move faster because they discovered a new route that will allow them to travel much of the four-and-a-half-mile distance on small four-wheeler-type vehicles, Adkins said.

“It won’t be nearly as strenuous as it was when we first initially went in there,” Adkins said.

Kevin Stricklin, an administrator for the U.S. Mine Safety and Health Administration, said air quality readings from the mine showed “a confluence of carbon monoxide, hydrogen and methane . . . in the explosive range.”

Rescue operations were first halted because of dangerous air quality caused by the explosion Monday afternoon. A second rescue attempt began Thursday morning when tests of air samples from a borehole drilled 1,100 feet from the top of the mine found conditions safe enough for teams to enter.

Four crews of eight rescue workers each advanced to within 500 feet of one of two airtight safety chambers when they were told to turn back. They were inside the mine for about four and a half hours, Adkins said.

The chambers are about 2,500 feet apart. Officials hope the four miners were able to enter them if they survived the explosion. Three miners are believed to be in or near one chamber, and the fourth miner in or near another.

The chambers contain enough food, water and oxygen to sustain miners for at least four days -- or at least until roughly Friday afternoon. The four-day supply is designed to sustain 15 miners.

Adkins said the rescue crews were “very angry” about being told to leave the mine and that officials were urging them to sleep to preserve their energy.

“They are running on adrenaline right now,” Adkins said.

The families “understand that if we have any hope of survival and they’re in the rescue chamber, they’re still OK,” West Virginia Gov. Joe Manchin III said. “I mean, that’s the sliver of hope we have. And it’s a long shot.”

In addition to the four missing miners, the bodies of 18 miners have yet to be recovered. Four of those have been identified, along with seven bodies that were pulled out of the mine after the explosion.

“The rescue attempt is still very valid,” the governor said.

Each crew member carried about 30 pounds of gear and breathing apparatus . They left some equipment at a basing station in the mine.

“When we are able to go back in, it won’t be nearly as strenuous as it was when we first initially went in there,” Adkins said, adding that a four-wheeler-type vehicle may be used to move crews quickly through the mine.

Mine safety authorities have warned family members that chances are slim for finding anyone alive.

“The odds are not in our favor because of the horrendous blast we had,” Stricklin said.

Manchin said many family members have remained at mine offices since shortly after the explosion rocked the complex Monday. Before the rescue mission began, Manchin outlined three scenarios to the 50 to 100 family members who were still there Thursday.

“This is not a scenario we wanted,” Manchin said.

Officials said the explosion occurred at 3:02 p.m. Monday as 31 miners were coming off the day shift. The blast knocked out lights, communications and ventilation fans, and created a windstorm that roared up shafts to the surface, shooting rocks, dirt and debris into the air.

After the blast subsided, several miners rushed inside and found six men dead and three injured; one of the injured later died. The other two remain hospitalized after the nation’s deadliest coal mining accident in more than a quarter of a century. One is in intensive care, Manchin said. The other is expected to be released from a hospital soon.

The names of the four missing men have not been released.

The cause of the explosion is undetermined, although the mine owner, Massey Energy Co., has come under increasing fire for a spotty record of safety operations at Upper Big Branch, including 10 citations this year for inadequate ventilation of explosive gases.

Over the last year, federal safety inspectors fined the company more than $382,000 for repeated serious violations involving its ventilation plan and equipment at the mine. The company was cited for failing to follow its safety plan, allowing combustible coal dust to accumulate and having improper firefighting equipment.

The Upper Big Branch mine was shut down temporarily for safety violations 29 times last year, Stricklin said. Massey was cited for 515 violations at the mine in 2009 and 124 so far this year.

Three workers have been killed at the mine in the last 12 years. A worker was electrocuted in 2003, another died after a roof collapse in 2001 and a third died when a beam collapsed in 1998.

The mine was cited for two safety violations Monday, the day of the disaster. But Stricklin said he was “very confident” that the infractions played no role in causing the explosion because they occurred several miles from the blast site.

david.zucchino@latimes.com

kim.geiger@latimes.com