Independent Review of MSHA's Actions at Crandall Canyon Mine

Considering this information, the area of the working section would have been severely
disrupted by the major bounce that occurred on August 6 th . Miners would have been knocked
down by the forces. The dust would have made breathing and visibility extremely difficult,
and may have remained suspended for several hours before settling. Orientation would have
been disrupted to the point that it would have been almost impossible to negotiate travel or
determine even which direction was inby or outby. The MSHA persons-in-charge stated they
thought that the trapped miners initially would have tried to travel outby. Once the miners
found that the entries were blocked they believed that the trapped miners would travel into
the No. 4 bleeder entry inby the pillar line and would have built a barricade. However, in the
reduced visibility, it would have been difficult to find their way to the No. 4 bleeder entry.
3) The low oxygen discovered by exploration parties over the rubble on August 6 th .
Shortly after the accident occurred, five of the Crandall Canyon miners who were outby the
extent of the bounce’s damage went to crosscut 120 of the South Barrier section to determine
what had happened and tried to reach the trapped miners. One of the miners, in his Accident
Investigation Team interview, stated “We got in two or three breaks and the oxygen dropped
down to like 16 percent,” and “we figured, oxygen being so low, let's pull back and work on
ventilation and get some air down to our guys.”
At approximately 7:30 a.m. on August 6 th , an exploration party of MSHA and mine rescue
team members entered the mine and advanced to the area of the bounce. Their mission was to
negotiate a route of travel over the rubble blocking the entries and to access the section in an
attempt to facilitate a rescue. Starting at crosscut 120, by crawling over the rubble and
maneuvering their way through the crosscuts and entries, they were able to advance to
crosscut 126. The working height in the area had been about 8 feet prior to the bounce, but
they described the entries so full of rubble that at times they were lying on their backs and
pulling themselves along by the wire mesh bolted to the roof. Their exploration was hindered
by reduced levels of oxygen. When the oxygen levels lowered to about 16% they also had to
retreat. The origination of the low oxygen and the fact that the oxygen content continued to
reduce as the exploration teams progressed inby seemed to be ignored by the persons-incharge
on site. It is likely from the low oxygen readings found by the exploration teams that
the section was inundated by the low oxygen at the time the bounce occurred.
4) The low oxygen detected from Borehole No. 1. On August 9 th , borehole No. 1
intersected the mine at approximately 10:00 p.m. in the South Barrier mining section. By 1:45
a.m. on August 10 th the samples reflected that the atmosphere in the intersected area contained
7.4% oxygen. Earlier, on August 6 th , mine rescue teams had breached seal No. 1 of the Main
West section adjacent to the South Barrier section and detected a concentration of oxygen in
the atmosphere similar to the 7.4% reading found at the borehole location. It appeared that
there had been a breach of the barrier separating the two sections and that the low oxygen had
migrated from the sealed section into the active South Barrier section. The miners on the
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