More than numbers: The dead of Idaho's Sunshine Mine

The statistics of Idaho’s worst mining disaster are still startling, even more than three decades after that fateful day in 1972, when an underground fire broke out in the Silver Valley’s Sunshine Mine: Ninety-one men dead, 77 women widowed and 200 children left fatherless. The oldest victim was 61, the youngest 19. More than half of the men who died from carbon monoxide poisoning in the silver mine were military veterans. The hardscrabble valley would never be the same.

Gregg Olsen brings those grim numbers to life in The Deep Dark. Never romanticizing the hard-working, hard-drinking culture, Olsen introduces readers to the families in the tight-knit Coeur d’Alene mining district. The men who died that day included 38-year-old Don Beehner, who, before he hired on with Sunshine, held "a succession of jobs with the mines, a paving company, or the railroad, interspersed with the births of two sons and two daughters."

Unlike coal mines, metal mines are not supposed to burn. The wood timbers in the Sunshine were soggy and should not have been capable of sustaining a fire for the many days that the Idaho fire raged. The exact cause of the fire, Olsen writes, remains unknown, but he describes one plausible theory. The polyurethane foam Rigiseal — developed in part by Dow Chemical and sprayed in the mine "to stop leakage and channel air flow" — was highly flammable, and had been banned in underground British mines since 1962. Six years before the Idaho fire, in 1966, the United States Bureau of Mines conducted its own test and also found the chemical a fire hazard, but oddly, took no action. "The only proof," Olsen writes, "that polyurethane foam was recognized as dangerous was that after the Sunshine fire, no American mines used the product underground."

Small comfort for the 91 miners and their families.

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