Early evidence also indicates that coal dust may have caused the explosion. The main explosion may have been initiated by a smaller methane explosion, which kicked large amounts of highly explosive coal dust into the air, causing a much larger secondary explosion:
After visiting the Darby mine on Saturday, Gov. Ernie Fletcher had said the evidence suggested a methane leak ignited, but added that damage from the blast about 5,000 feet into the mine reached the surface.Even more troubling, according to Oppegard, is that MSHA had cited the mine 47 times since April 2001 "for not cleaning up coal dust and other combustible material, not properly maintaining or failing to properly apply crushed limestone -- known as rock dust -- to minimize the danger of coal dust explosions."
“We had a fairly extensive explosion that blew out with such force that even the mine entry … had a tremendous amount of discharge to the point that debris punctured oil cans that were about probably, I’d say, 200 or 300 feet from the mine opening,” Fletcher said.
That kind of force most likely came from a coal-dust explosion, Tony Oppegard, former general counsel to Kentucky’s mine safety agency, said Sunday.
“Anytime you have an explosion that rips through a mine and travels 5,000 feet and is felt on the surface, that is almost assuredly a secondary coal dust explosion if not a primary dust explosion,” Oppegard said.
“Rock dust suppresses fire, supresses explosions,” he said. “There are many recorded cases, and the Sago Mine (in West Virginia, where 12 miners died Jan. 2) is an example, where a methane explosion was confined to the immediate area because the mine was well-rock-dusted.”The Kentucky legislature passed a law requiring mines to store breathing devices underground and to set up lifelines to help miners find their way out, but it doesn't take effect until July.
The MSHA records show that the Darby mine was fined once for $500 for not cleaning up coal dust or other combustible materials, but many of the other violations carried the minimum penalty of $55 or $60.
“These are not nit-picky violations,” Oppegard said. “Those are crucial to mine safety and it’s unfortunate that a lot of operators consider them to be nit-picky violations and unimportant.”
One miner, Paul Ledford, survived the blast and was found unconscious near the mine's entrance. According to his brother,
There were problems with his brother's rescue breather that was supposed to provide him with an hour's worth of clean air.Yesterday's deaths brought to 31 the number of coal miners killed during 2006, a year that began with the Sago mine tragedy, where one miner was killed in an explosion and 11 others suffocated to death while awaiting rescue. Twenty-two coal miners were killed in all of 2005. Ten Kentucky miners have been killed this year, compared with 8 in all of 2005.
"He said his didn't last five minutes," he said.
More stories on recent mine safety problems can be found here.