The Sunshine silver mine is situated about eight miles from the town of Kellogg, today a city of just over two thousand inhabitants in the foothills of the Rocky Mountains. The city straddles Route 90 in the northwest of the State of Idaho, around 420 miles from Seattle. In 1972 Kellogg was almost twice the size it is today and a prospering community. That year a disaster at the mine took the lives of 91 out of the 173 men who were underground at the time. The Sunshine silver mine disaster is seen as having been the trigger for significant legislation that took place over the following years, and for stimulating Congress to change the way the US Government oversaw the mining industry.
The mine was opened in 1884 and continued operations through to 2001 when falling silver prices were given as the reason for its closure. For decades it was known as the richest, most productive silver mine in the world, and as such was a source of pride in the region.
The Sunshine miners came from a close community, built around Kellogg and other towns in the Coeur d’Alene district, which, over more than three generations, has developed its own attitude and approach to the dangers of working underground.
“The greater the danger, the more reckless men became. It was a mix of laziness, tempting fate for the buzz of adrenaline, and just plain ignoring the obvious. More men were hurt and even more died because someone decided to push something to a new limit. Miners sometimes took the extra step toward trouble. Trouble could be a rush.” (Olsen, 2004.)
A metal mine was regarded as presenting different dangers from those found in a coal mine where methane gas and fire are considered as ever-present hazards. At Sunshine, the most feared danger was a rock burst, the explosive collapse of a roof of a tunnel under the enormous surrounding pressure.
The total length of all the tunnels at Sunshine was approximately 180 miles. The miners gained access to the active workings by walking along a 200 foot drift (tunnel) to a shaft, where they were lowered to the 3100 and 3700 levels by means of a hoist (elevator) from where they traveled by train to the No. 10 shaft and were again lowered down that shaft to the levels where they were to work. The No. 10 shaft extends from 3100 to the 6000 feet.
In 1972 mining continued on the 4000, 4200, 4400, 4600, 4800, 5000, and 5200 levels, with some development work on the 5800 level. Elsewhere the tunnels where the silver had been exhausted and access was no longer required were sealed off.
On May 2nd at around eleven thirty in the morning, when all 173 men of that shift were underground, miners on the 3700 foot level detected smoke coming down a foot ascent/descent identified on the ventilation map as the 910 ‘raise’. (Sunshine Map). At the discovery the smoke was comparatively light, but developed quickly into a heavy, dark, choking stream.
Initially the foremen and miners in the location focused on trying to ascertain what was causing the smoke and where was the location of its source. An explosive sound, believed to be the destruction of a wall built to seal off a disused tunnel was heard. Subsequently the speed of the spread of the cloud of smoke increased rapidly. The collapse of the seal is believed to have contributed to the creation of a situation where the installed air extraction and input fans created a kind of ventilation ‘short circuit’ – an accelerated recycling of the gas through the areas of the mine where most men were located.
Methane Gas is more widely understood now than in 1972. The increasing interest in alternative fuels has increased interest in methane known popularly as ‘natural gas.’ While methane’s explosive properties at even low atmospheric proportions present its greatest danger, it is also a rapidly effective asphyxiant. As was the practice at Sunshine, the miners were either not wearing their protective masks against gas, or the equipment was corroded and defective.
The originating cause of the fire is not known although the approximate location has been thought to be in a tunnel which was no longer active and had been sealed off as was normal practice. This approach meant that the disused areas of the mine were at best infrequently inspected. One reason why there was little concern with this practice was that the mine was considered to be a ‘hot’ damp mine where temperatures could exceed 100° F at conditions of 100% humidity, creating poor conditions for the creation and spread of fire. Old timbers and material left behind the sealing walls were thought to be damp and decomposing within a rock environment that would not burn or conduct fire.
Bob Launhardt, the Safety Engineer on duty the morning of the fire, describes the generally accepted location of the start of the fire :-
“To have a fire, one must have fuel, air (oxygen) and sufficient heat to initiate combustion of the fuel-air mixture. The investigators quickly reached a consensus that the fire began at or near the 3400-09 ventilation bulkhead. Combustible material in the fire zone included a bulkhead constructed of timber and plywood and coated with rigid polyurethane foam, located in a mined-out area containing significant amounts of timber used for ground support and passageways.” (Launhardt, 1997)
Polyurethane foam (‘Rigiseal’, manufactured by the Dow Chemical Company) was used in underground mines throughout the USA. Its functions were to create a rigid, durable seal and to bind together elements of rock where there was a possibility that fracturing might take place. While there was general use of this material in America, following tests of its flammability in Great Britain in 1962 it had been banned from use underground In 1966, the United States Bureau of Mines also tested the material.
“After two years of research on sealants and coatings, the Bureau of Mines published a report on polyurethane foam. Fire hazard from foam exists if flame propagates beyond the ignition source or penetrates the foam….Foam on the ribs and adjoining roof presents a fire hazard. Flame propagated in all tests with foam on the ribs and across the roof.” (Mitchell, Murphy and Nags, 1966). However, no action was taken to follow up on this report.
J. Davitt McAteer, a member of Ralph Nader’s investigative team was present at the mine shortly after the accident was known. In a document produced later he summarizes the reasons given by the USBM for the accident as follows.
1. Ineffectiveness of the warning system.
2. Delay in beginning mine evacuation.
3. Ineffectiveness of the mine communication system.
4. Inadequacy of the emergency escape-way system.
5. Inadequacy of the emergency fire plan.
6. Use of a series ventilation system.
7. Failure to seal abandoned areas of the mine.
8. Failure to monitor the mine atmosphere.
9. Failure to construct incombustible ventilation bulkheads.
10. Lack of remote controls on major underground fans. (McAteer, 1981)
This “official” view of the causes of the disaster as expressed by the US Bureau of Mines is not accepted by Bob Launhardt.
“In my opinion, the USBM “Final Report” failed to properly address the two most important safety deficiencies affecting the Sunshine Mine Fire—the potential for a short-circuit between the exhaust airway and the intake airways, and the fire hazard of using polyurethane foam to seal a critical ventilation control bulkhead. …… In combination, the two safety deficiencies turned a fire in an inactive part of the mine into a disaster that killed more than half the crew working at the time….Without the short circuit, almost all the combustion products from the polyurethane foam- induced, fuel-rich fire would have gone harmlessly to the surface. Without the polyurethane foam, there would have been no accelerant to produce rapid combustion and the large volume of deadly smoke and gases.”
Launhardt was on duty underground up to some thirty minutes before the smoke was reported. As described by Olsen and others, he appears to have been a professional, conscientious and hard-working man. As a salaried engineer he was regarded by the miners as one of ‘them’ not one of ‘us’ and he lacked the natural empathy to build the bridges needed to cross that gap. report on the disaster with the purpose of deception.
As Olsen presents in his book, the Sunshine miners had developed a dismissive attitude towards management’s reaction to the dangers of their environment. He implies that a kind of macho peer pressure led to the miners ignoring the instructions intended by management for their care and safety, arguing that the miners on the job knew what was, and what was not, necessary.
The USBM report goes further in claiming that Mining Company had not ensured that the men were trained in the use of the ‘self-rescuers’ (gas mask equipment) available. Launhardt however points out that this equipment was not at that time required in hardrock mines, and that Sunshine Mine was the only such mine in the USA that used them.
Launhardt makes it clear that, despite his responsibilities neither he nor his colleagues had any knowledge of the fire hazard presented by polyurethane foam prior to the fire. However he makes the case that the senior management of the USBM knew of its dangers. Launhardt goes as far as to suggest that the report issued by the USBM was a cover-up of the real reasons for the vast loss of life:
“Had the USBM issued an official report on the fire based upon what they knew about polyurethane foam’s impact on fires, the would in effect have conceded pending litigation to the plaintiffs. Several lawsuits had been filed in behalf of widows. children, and families, seeking damages for wrongful death of the 91 victims. Claims were also filed to recover damages to the mine, loss of production and other related costs. The U.S. Government was among the defendants. The key issue in the litigation was the premise that, but for the combustion of rigid polyurethane foam at the 3400-09 intersection, the fire would not have been a disaster.” (Launhardt Part IX, paragraph 1.)
Prior to the Sunshine disaster, the USBM conducted both mining research and limited enforcement activities. In the scrutiny which followed the disaster this arrangement was found to present a serious conflict of interest. The research and advisory activities remained within USBM, but its enforcement activities were transferred to a newly created authority – the Mining Enforcement and Safety Administration (MESA) in 1973 which itself was incorporated into the Federal Mine Safety and Health Administration (MSHA) in 1977.
The MSHA act of Congress consolidated all federal health and safety regulations of the mining industry, coal and non-coal, under a single statutory authority and transferred responsibility for this activity from the Department of the Interior to the Department of Labor. The act strengthened and expanded the rights of miners, and extended the protection of miners against retaliation for exercising such rights. Importantly the act established an independent Federal Review Commission over MSHA’s enforcement actions.
Despite this change, to this day there is a question raised about the ability of Mine Safety and Health Administration to carry out its responsibilities in a fully impartial manner.
“The perception of accident investigators, often employed by the mining companies, being “too close” or inclined to protect their employer has lingered in industrial accidents since the creation of MSHA. Such a perception – that Congress and the public are not getting hardnosed, facts-only investigations – is accurate. Now is an opportune time for Congress to reopen this debate.” (Robert Ferriter, Director of the Mine Safety Program at the Colorado School of Mines in Golden, 2005, quoted in Geotimes).
Since 1977, fatalities in U.S. coal mines decreased from 272 in that year to 86 in 2000. 2005 was a new low with just 22 fatalities in a workforce of 40,000 underground coal miners.
While it is unlikely that the causes of the fire at the Sunshine mine will now be agreed, it is clear that the accident did contribute to an increase in governmental willingness to establish regulations binding mining companies to protect the safety and health interests of their employees, and to enforce their observance. An open question remains as to whether the government and the powerful commercial interests involved effected a cover-up to prevent litigation against them.