Rescue crews battled to move heavy drills to reach four missing miners today at a West Virginia coal mine where an explosion killed 25 others in the deadliest US mining disaster in decades.
Initial search crews reported damage so severe at the Upper Big Branch Mine after Monday's explosion that train rails in the mine "looked like they had been twisted like a pretzel", said Governor Joe Manchin.
"It had to be an horrific explosion to cause that kind of damage," Mr Manchin told a news briefing.
Crews planned to drill four holes into the mine in Montcoal, owned by Massey Energy, Mr Manchin said. Drilling may not begin until tomorrow as the rigs are not yet in place an access road must be ploughed to the site.
Efforts were hampered by the hazardous build-up of methane gas and smoke underground, posing a danger that forced the earlier teams back from the search area 30 miles (48 km) south of the state capital Charleston.
"It's a slow process," Mr Manchin said. Three of the holes were for ventilation, and rescuers were targeting an area some 1,100 feet (335 metres) below the surface, he said.
Miners' families remained hopeful, the governor said.
"I don't want to give anybody any false hope but ... we're still seeing people clinging on to hope," he said. "We are hoping that we can still, by a miracle, recover some miners."
Shares of Massey Energy fell more than 10 per cent on the New York Stock Exchange. The Richmond, Virginia-based Massey is the largest coal producer in Central Appalachia, operating in West Virginia, Kentucky and Virginia.
Massey said on its website its accident rate fell to an all-time low in 2009, which was the sixth consecutive year its safety record was stronger than the industry average.
But according to federal records, the Upper Big Branch Mine has had three fatalities since 1998 and has a worse than average injury rate over the last 10 years. Two miners died in roof collapses in 1998 and 2001, and a third was electrocuted in 2003 when repairing an underground car.
Kevin Stricklin of the US Mine and Safety Health Administration said: "Something went very wrong here for us to have the magnitude of this explosion.
"We'll leave no stone unturned to get to the bottom and tell you exactly what was not going right here," he said.
The governor said 18 miners remained inside the Upper Big Branch Mine, and 14 of them were dead.
"We don't know the fate of four," Manchin said.
Michelle McKenney, daughter of Benny Willingham, who was among those killed, said she was angry at Massey for not contacting them.
"No one from Massey has called my mother or any of us children or his mother. He still has a mother that is home grieving," she said.
The federal government was ready to assist in the rescue operation, President Barack Obama said at a White House gathering of religious leaders for a prayer breakfast.
"Pray for the safe return for the missing, the men and women who've put their lives on the line to save them, and the souls of those who've been lost in this tragic accident," the president said.
The mine, owned by Massey's Performance Coal subsidiary, has two emergency chambers stocked with food, water and enough air to survive for four days, and rescuers hoped the missing miners had made their way there.
Massey CEO Don Blankenship said the company was "taking every action to locate and rescue those still missing."
Ellen Smith, the editor of Mine Safety and Health News, said the Upper Big Branch mine had been repeatedly cited for safety violations going back years and continuing this year.
The death toll makes it the deadliest US mining disaster since 1984, when 27 miners died in a fire in Utah, according to the United States Mine Rescue Association.
The Montcoal disaster occurred just as China was celebrating the rescue of more than 100 miners from a flooded coal mine. The miners endured more than a week underground.
Five miners died in the Chinese mine in Xiangning, in the northern province of Shanxi, and 33 were still missing.
In the worst coal mine disaster in US history, 362 miners died in an explosion in 1906 in West Virginia's Monongah mine.
Reuters