Mine Safety and Health Administration (MSHA) - Report of ...

EXECUTIVE SUMMARY
The August 6 and 16 Accidents
The Crandall Canyon Mine, in Emery County, Utah, was operated by Genwal Resources Inc
(GRI), whose parent company was acquired by a subsidiary of Murray Energy Corporation in
August 2006. On August 6, 2007, at 2:48 a.m., a catastrophic coal outburst accident occurred
during pillar recovery in the South Barrier section, while the section crew was mining the barrier
near crosscut 139. The outburst initiated near the section pillar line (the general area where the
miners were working) and propagated toward the mine portal.
Within seconds, overstressed pillars failed throughout the South Barrier section over a distance of
approximately ½ mile. Coal was expelled into the mine openings on the section, likely causing
fatal injuries to Kerry Allred, Don Erickson, Jose Luis Hernandez, Juan Carlos Payan, Brandon
Phillips, and Manuel Sanchez. The barrier pillars to the north and south of the South Barrier
section also failed, inundating the section with lethally oxygen-deficient air from the adjacent
sealed area(s), which may have contributed to the death of the miners. The resulting magnitude
3.9 seismic event shook the mine office three miles away and destroyed telephone communication
to the section.
Federal and local authorities responded to the accident. MSHA issued an order pursuant to section
103(k) of the Mine Act that required GRI to obtain MSHA approval for all plans to recover or
restore operations to the affected area. Mine rescue teams were organized, a command center was
established, and a rescue effort was initiated. After unsuccessful attempts to reach the miners by
crawling over the debris, GRI developed a rescue plan, approved by MSHA, to access the
entrapped miners by loading burst debris from the South Barrier section No. 1 entry using a
continuous mining machine. These efforts began on August 8 at crosscut 120.
On August 16, 2007, at 6:38 p.m., a coal outburst occurred from the pillar between the No. 1 and
No. 2 entries, adjacent to rescue workers as they were completing the installation of ground
support behind the continuous mining machine. Coal ejected from the pillar dislodged standing
roof supports, steel cables, chain-link fence, and a steel roof support channel, which struck the
rescue workers and filled the entry with approximately four feet of debris. Ventilation controls
were damaged and heavy dust filled the clean-up area, reducing visibility and impairing breathing.
Also, air from inby the clean-up area containing approximately 16% oxygen migrated over the
injured rescue workers. Nearby rescue workers immediately started digging out the injured miners
and repairing ventilation controls. Two mine employees, Dale Black and Brandon Kimber, and
one MSHA inspector, Gary Jensen, received fatal injuries. Six additional rescue workers,
including an MSHA inspector, were also injured.
Underground rescue efforts were suspended while a group of independent ground control experts
reevaluated conditions and rescue methods, although surface drilling continued. In total, seven
boreholes were drilled from the surface to the mine workings. Each successive borehole provided
information as to conditions in the affected area and helped to determine the location of the next
hole. None of the boreholes identified the location of the entrapped miners. Ultimately, it was
learned that the area where the miners were believed to have last been working sustained extensive
pillar damage and had levels of oxygen that would not have sustained life.
Explanation of the August 6 Collapse
The August 6 collapse was not a “natural” earthquake, but rather was caused by a flawed mine
design. Ultimately, it is most likely the stress level exceeded the strength of a pillar or group of
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