2007 –Aug 6, Crandall Canyon Coal Mine Wall Collapse (3 rescuers die Aug 16), Emery Co., UT-9
— 9 Foy (AP). “Utah’s Deep Coal Operators Face Heavy Regulation,” WP, June 28, 2009.
— 9 MSHA. Crandall Canyon Accident Investigation. Summary and Conclusions.
— 9 Salt Lake Tribune, UT (Robert Gehrke). “Crandall Canyon bombshell…” 1-17-2008.
MSHA: “On August 6, 2007, six miners were killed in a catastrophic coal outburst when roof-supporting pillars failed and violently ejected coal over a half-mile area. Ten days later, two mine employees and an MSHA inspector perished in a coal outburst during rescue efforts.
- The August 6 catastrophic accident was the result of an inadequate mine design.
- Flawed engineering analysis by Agapito Associates Inc. (AAI), resulted in an inadequate mine design, with unsafe pillar dimensions, which contributed to the accident.
- AAI’s inadequate engineering management review also contributed to the accident.
- The mine operator, Genwal Resources Inc. (GRI), submitted a mining plan based on the AAI analysis.
- GRI failed to revise its mining plan following coal bursts in March and as late as August 3, but rather continued to mine coal in areas with unsafe conditions.
- GRI’s unauthorized mining practices increased geological stress levels in the vicinity of working coal miners.
- MSHA found no evidence that a naturally occurring earthquake caused the collapse on August 6….
- Any hope of accessing the trapped miners required rescue personnel to remove coal debris that blocked them from the miners.
- The mine operator withheld information about a recent coal burst which deprived MSHA of a complete picture of underground conditions.
- The unexpected conditions in the mine caused a robust roof control system to fail during the attempt.
“Genwal Resources Inc. Actions
- GRI misled MSHA about the extent of the March 10 coal burst and failed to immediately inform MSHA about the March 7 and August 3 bursts.
- GRI submitted an inadequate roof control plan based on faulty AAI engineering analyses to MSHA.
- GRI failed to adequately revise its roof control plan to provide better support after the March 7, March 10, and August 3 bursts and continued to expose miners to unsafe conditions.
- GRI violated the approved roof control plan when coal was mined in a prohibited area.
Agapito Associates Inc. Actions:
- AAI failed to recommend safe mining methods and pillar/barrier dimensions.
Fines:
- MSHA levies $1,636,664 in fines against GRI
- MSHA levies $220,000 against AAI.
….
(Mine Safety and Health Administration, U.S. Dept. of Labor. Crandall Canyon Accident Investigation. Summary and Conclusions.)
Salt Lake Tribune, Jan 17, 2008: “Newly released meeting minutes show that, in the months before the Crandall Canyon mine disaster, its co-owners were dealing with serious structural problems, higher-than-expected costs and subpar coal, but were hopeful that plans approved by federal regulators would get things back on track. Those plans hinged on extracting nearly all of the coal from the south barrier pillar, the 450-foot-thick coal wall that helped support the roof of the mine, where three months later the walls collapsed, entombing six miners. Three other men were killed in the subsequent rescue effort. The minutes show that Robert Murray, co-owner of the mine, knew of the severe mine “bounce” on March 10 that forced the mine to shut down and reposition its operations. Murray, who led the rescue effort in August, said at that time he had no knowledge of the bounce….” (Salt Lake Tribune, UT (Robert Gehrke). “Crandall Canyon bombshell: Months before deadly cave-ins, owners knew of structural woes.” 1-17-2008.)
Foy, June 28, 2009: “Two years after a Utah mine collapsed, entombing six miners more than 2,000 feet under a mountain and also killing three members of a rescue team, the state’s coal operators are backing away from rich coal reserves held deep under the ground.
“Coal mines have come under intense scrutiny in every part of the country, with the Mine Safety and Health Administration tripling fines against all coal mines last year, to $152.7 million.
“But in Utah, where easy access to coal was exhausted more than a decade ago, operators say they have been hit especially hard because of the extreme depths at which they dig for coal. The risks are compounded by a common method of coal removal called retreat mining, which has operators sometimes flirting with disaster by deliberately inducing cave-ins.
“The Crandall Canyon collapse in 2007 shows what can go wrong. A bounce, a type of seismic jolt, imploded with the force of two million pounds of explosives at Crandall, said Michael McCarter, a professor of mining engineering at the University of Utah. The tremor flattened a section of the mine roughly the size of 63 football fields, leaving six miners entombed 2,160 feet under mountain cover. Another cave-in 10 days later killed three members of a rescue team, including a federal mining inspector.
“Federal regulators, stung by criticism following mine disasters from West Virginia to Utah, quickly clamped down.” (Foy, “Utah’s Deep Coal Operators Face Heavy Regulation,” WP, 6-28-2009.)
Sources
Foy, Paul (AP). “Utah’s Deep Coal Operators Face Heavy Regulation,” Washington Post, June 28, 2009. At: http://www.washingtonpost.com/wp-dyn/content/article/2009/06/28/AR2009062801308.html
Mine Safety and Health Administration (MSHA). Crandall Canyon Accident Investigation. Summary and Conclusions. Arlington, VA: MSHA, U.S. Department of Labor. Accessed 8-20-2015 at: http://www.msha.gov/Genwal/ccSummary.asp
Mine Safety and Health Administration (MSHA). Single Source Page for Genwal Resources Inc. Crandall Canyon Mine. Mine ID: 4201715. Arlington, VA: MSHA, U.S. Department of Labor. 9-30-2013 update. Accessed 8-20-2015: http://www.msha.gov/Genwal/CrandallCanyon.asp
Salt Lake Tribune, UT (Robert Gehrke). “Crandall Canyon bombshell: Months before deadly cave-ins, owners knew of structural woes.” 1-17-2008. Accessed 8-20-2015 at: http://www.sltrib.com/ci_7994785