Read the order here.

CHARLESTON, W.Va. -- State mine safety officials late Friday ordered emergency inspections of up to 500 rescue shelters in West Virginia's underground coal mines, citing concerns that cracked valves and fittings might make the units inoperable.

The order from the Office of Miners Health, Safety and Training requires inspections by shelter manufacturers of all inflatable, "tent design" mine rescue chambers by Oct. 31.

The five-page order also requires mine operators to replace all brass valves and fittings associated with the units' compressed-oxygen cylinders within the next two years.

Plans for this required retrofitting must be submitted to the state by Oct. 31, but the deadline for actual replacement of valves and fittings is not until Dec. 31, 2013.

"We have to make sure they are going to operate the way they are designed to operate," said state mine safety director C.A. Phillips.

Mines across West Virginia are required to contain specially designed rescue shelters that could help miners survive the toxic environment inside a mine after an underground explosion.

West Virginia lawmakers mandated the equipment after the Sago Mine disaster and the Aracoma Mine fire, in which workers died before rescuers could reach them in smoke-filled underground tunnels.

The order comes after a lengthy behind-the-scenes state and federal investigation following an incident at an unidentified underground mine in January, where officials originally believed a tent-design shelter had been vandalized.

Read the order here.

CHARLESTON, W.Va. -- State mine safety officials late Friday ordered emergency inspections of up to 500 rescue shelters in West Virginia's underground coal mines, citing concerns that cracked valves and fittings might make the units inoperable.

The order from the Office of Miners Health, Safety and Training requires inspections by shelter manufacturers of all inflatable, "tent design" mine rescue chambers by Oct. 31.

The five-page order also requires mine operators to replace all brass valves and fittings associated with the units' compressed-oxygen cylinders within the next two years.

Plans for this required retrofitting must be submitted to the state by Oct. 31, but the deadline for actual replacement of valves and fittings is not until Dec. 31, 2013.

"We have to make sure they are going to operate the way they are designed to operate," said state mine safety director C.A. Phillips.

Mines across West Virginia are required to contain specially designed rescue shelters that could help miners survive the toxic environment inside a mine after an underground explosion.

West Virginia lawmakers mandated the equipment after the Sago Mine disaster and the Aracoma Mine fire, in which workers died before rescuers could reach them in smoke-filled underground tunnels.

The order comes after a lengthy behind-the-scenes state and federal investigation following an incident at an unidentified underground mine in January, where officials originally believed a tent-design shelter had been vandalized.

State officials now describe the incident, involving an A.L. Lee Corp. shelter, as a "catastrophic failure" that pressured the interior of the steel structure.

"The initial determination is that the pressure build-up inside the container forced open both the tent deployment door and the air-lock access door, ejecting a supply container and three five-gallon water containers from the access door area onto a nearby [mine wall]," according to a U.S. Mine Safety and Health Administration report on the event.

In Friday's order, state officials said that "subsequent analysis of the failed shelter led to the discovery of cracks on multiple valves and fittings and identification of fittings that did not meet" recommended specifications.

A.L. Lee reported in February that it found similar problems with two other units that had been returned to its shop, according to MSHA records. State inspectors apparently found similar problems on shelters made by other manufacturers, records show.

"The demonstrated unpredictable service life of the brass valves and fittings is troublesome," the state said in Friday's order. "The current situation left unchecked represents a safety hazard."

MSHA officials had recommended examination and possible replacement of problem valves and fittings as early as January, but Friday's state order appears to be the first time regulators have mandated any action.

Amy Louviere, a spokeswoman for MSHA, said her agency has been working closely with the state and "will be issuing follow-up actions shortly."

The state's Friday order refers to a previous order, dated Sept. 29, but that order has not yet been made public.

Some inspections and retrofits of shelters already might have occurred, but it's not clear how many. Friday's order requires records of those inspections - being conducted by manufacturers -- to be submitted to the state.

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.