Seven miners are dead and 19 are missing after an explosion at an underground coal mine in West Virginia that has a record of violations due to ventilation problems, officials said.
The blast occurred around 3 p.m. local time at Massey Energy's Upper Big Branch mine, state mining director Ron Wooten said. The mine is situated in Raleigh County, about 48 kilometres south of Charleston.
Massey Energy Co. CEO Don Blankenship issued a statement late Monday in which he said the company has launched a rescue effort to locate the missing miners.
"We want to assure the families of all the miners we are taking every action possible to locate and rescue those still missing," Blankenship said. Miners' names would not be released pending notification of next of kin, he added.
Nine rescue teams made up of six members each that are specially trained for operations at mines are on scene, according to Amy Louviere, a spokesperson for the U.S. Mine Safety Health Administration.
Elizabeth Pellegrin, a spokesperson for the Charleston Area Medical Center, said one injured miner is in intensive care. Pellegrin also said the facility is "preparing for other patients."
The mine is operated by a subsidiary of Massey Energy called Performance Coal Co. The company has not yet commented on the extent of the damage from the blast.
The explosion's cause remains unknown. But government records show that large amounts of methane gas are released into the mine every day.
Methane is dangerous for miners. It's colorless and odourless, and can be explosive in high enough concentrations. Mines use powerful fans to dissipate it.
The mine spreads out across several square kilometres and has19 openings. It sits in one of the more heavily mined regions of West Virginia.
All communication lines inside the mine were severed in the explosion. But there are rescue chambers near the location of the blast trapped miners could use to survive for four days, if they can reach them.
About 200 employees work at the mine, which produced approximately 1.1 million metric tons of coal in 2009, according to data from the MSHA.
Three workers have died at the mine over the last dozen years.
A worker was killed in 1998 by falling bags of cement when a support beam collapsed. That accident was blamed on poor welding and construction.
In 2001, a part of a roof caved in, killing one worker. In 2003, an electrician was electrocuted and killed while repairing a shuttle car.
In West Virginia, all underground mines must have wireless communication and tracking systems that are built to withstand explosions and other disasters.
The number of miners killed at work in the United States fell for a second straight year in 2009, to 34. That was down from a previous low of 52 in 2008.
According to the MSHA, 18 of the deaths occurred in coal mines, while 16 were in gold, copper and other mines.
With files from The Associated Press
