Saturday, May 18, 2024

Sunshine Mine disaster rewind

by Richard Sheldon
| May 8, 2020 1:00 AM

What rankles in Bob Launhardt’s mind is the issue of what caused the disastrous and deadly 1972 Sunshine Mine fire that caused the deaths of 91 miners.

Robert E. (Bob) Launhardt was born in 1931 into a Midwest farm family, the second of five children. By the time he was 8 he was doing all the farm’s tractor work. The Great Depression required much hard work from all family members in order to hang onto the land.

His early education was almost entirely in Lutheran schools, in preparation for the ministry. But, he learned the ministry was not for him. He tried to enlist in the Army but was rejected as being physically unfit. In March of 1954 he was hired to work at the Silver Valley’s Sunshine Mine in Idaho. Over the next seven years he became active in the United Steelworkers Union and the AFL-CIO.

In 1961 Bob was appointed to the job of Safety Engineer to help Sunshine Mine improve its safety performance.

Bob’s memories of what happened May 2, 1972, are still vivid and retain details that are haunting to this day. He recalls that most of the 91 miners who died were well known to him. The rescue of the last two miners after they had been trapped for over a week brought him much joy. Forty-three fire survivors interviewed by USBM personnel said self-rescuers saved their lives.

The government said “spontaneous combustion.” Bob disagreed and convincingly argued that it was the polyurethane foam (PUF) Rigimix used as a sealant as needed on walls and ceilings in the mine’s ventilation circuits. That product had been shown to be highly combustible when applied on adjacent surfaces. When burned, it produced 10 times more CO than wood and paralyzing deadly cyanide gas. These issues had been known for six years prior to the disaster.

The “Root Cause Analysis” post disaster investigations went on for years. Included in the findings was the fact that, in 1969, Britain had found PUF to be highly flammable and banned its use in their mines and had ordered it stripped from its mines years before.

In 1986, PUF used to insulate a section of the main intake airway in the Kinross gold mine in South Africa burned, quickly killing 176 miners. Radio news reported the mine boss saying, “They told us it wouldn’t burn!”

The rich history of the Silver Valley of Idaho teaches us many lessons. The yearly memorial held each May 2 reminds us that we must never forget what the brave and hard-working miners of the Sunshine Mine taught us. If we forget this history and don’t learn its lesson, we will repeat it. Unfortunately, this year’s memorial was unavailable due to the ongoing COVID-19 restrictions.


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Bob Launhardt’s mining blog can be found at

Reviewed and edited by Robert E. Launhardt and Deborah Mitchell.