West Virginia regulators have cited a mining company for allowing workers in September to carry damaged emergency equipment into the Sago Mine, where an explosion nearly a year ago led to the deaths of 12 men.

The heat indicators on six miners' emergency air packs showed the packs had been exposed to temperatures above 130 degrees, according to the citation. Excessive heat can damage rubber parts, such as air hoses. The manufacturer warns miners not to use the packs if the heat sensor turns red.

The inspector said most of the miners at the Sago Mine did not know the devices had heat indicators, and had not been taught to check the indicator every day.

State regulators did not immediately respond to a question about how much the company would be fined.

The violation notice was issued on Sept. 7 to a subsidiary of International Coal Group Inc. A copy was obtained Thursday by The Associated Press.

ICG spokesman Ira Gamm said the company is contesting the citation and disputes the state inspector's assertion that the miners were not trained.

Eleven miners died of carbon monoxide poisoning at the Sago Mine following the Jan. 2 explosion. A 12th miner was killed by the blast. The sole survivor, Randal McCloy, Jr., has said that four members of his 12-man crew could not get their air packs to work after the explosion.

Failing to provide every miner with a functioning air pack and failing to train miners to use the device are violations of West Virginia law.