Independent Review of MSHA's Actions at Crandall Canyon Mine

ACCIDENT OVERVIEW
THE ACCIDENT ON AUGUST 6, 2007
In the early morning hours of August 6 th , a violent bounce of coal pillars occurred in the South
Barrier section of the Main West area of the Crandall Canyon Mine. The bounce registered 3.9
on the Richter scale, as measured by the University of Utah in Salt Lake City. (All bounce
magnitudes listed in this report are local Richter scale magnitudes.) At the time of the
accident, six miners were in the process of extracting coal on the section near crosscut 139. The
bounce was so catastrophic that the coal pillars failed outby crosscut 139 to crosscut 120, a
distance of approximately 2600 feet. Ventilation controls were damaged or destroyed outby to
crosscut 95, approximately 4500 feet from crosscut 139. The six miners were entrapped on the
section.
Attempts to contact the six miners on the section proved futile. A repairman, who had just left
the South Barrier section in a truck, was near crosscut 108 when he felt the air blast from the
bounce. He stated the dust from the bounce was so thick that he could hardly see. He
continued to travel outby where he met a co-worker, and they returned to the South Barrier
area. They were soon joined by three other miners. They attempted to find a way to the
trapped miners by traveling over coal rubble in the entries, but they withdrew due to low
oxygen. The Conspec® operator (dispatcher) on the surface tried to contact the miners by
mine phone and electronic paging, but received no response.
THE RESCUE ATTEMPT
MSHA was notified of the accident by mine management and responded with personnel and
equipment to help facilitate a rescue operation. The Company mine rescue team and other
area teams were also notified and responded. Upon the initial exploration by MSHA and
rescue team personnel, they found all four entries of the South Barrier section filled with
rubble beginning at crosscut 120.
Several approaches were taken during the rescue effort to reach the missing miners. First,
MSHA and mine rescue team personnel attempted to find a way over the rubble in each of the
four entries of the South Barrier section, similar to what Company personnel had tried
immediately after the accident. Again, because of low oxygen, this effort was unsuccessful.
Second, on the afternoon of August 6 th , an excursion by mine rescue personnel wearing
breathing apparatus was attempted into the Main West sealed area. This area ran parallel to
the South Barrier section, and rescuers hoped that access could be gained around the coalfilled
entries. However, the area just inby the seals was blocked by roof falls and/or unsafe
roof. After the team returned to the fresh air base, command center personnel asked them to
try a different route in the sealed area. As the team was preparing to re-enter the sealed area, a
significant bounce occurred. The bounce, which registered 1.9 on the Richter scale, forced low
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