W.R. Grace made millions from the local vermiculite mine, producing fireproof house insulation among other products. What you learn early in the film is what town residents didn't discover until it was too late - that the vermiculite mined at Libby contains asbestos. The toxic dust affected not only the men who worked at W.R. Grace, but the wives who washed their contaminated clothing and the children who hugged their fathers' dust-covered legs at the end of the workday. You also learn that asbestos-laden insulation from W.R. Grace's Libby operation can be found in as many as 35 million American homes.

As with other hard-hitting High Plains Films documentaries, Libby, Montana employs no narration. Instead the story emerges through the voices of its characters, including the EPA's heroic front-line clean-up man, Paul Peronard, and the asbestosis victims who tell their stories, punctuated by coughs and gasps.

Equally powerful, and strangely moving, is the footage of W.R. Grace mine manager, Earl Lovick giving - or, rather, resisting - testimony in a court deposition regarding his and his company's responsibility for the sickness and death of hundreds of employees. In his 70s at the time of the testimony, Lovick appears defiant, yet oddly unmoored, a man faced with the awful truth of his complicity. He himself was suffering from asbestosis when he died in 1999.