Coal/Ore Shovel Operator

Excavator was working in Redwine pit, highwall collapsed causing rock to fall on excavator. This caused a fatal injury to operator.

On Wednesday, December 7, 2011, at 7:33 a.m., Richard N. Yonts, a 49-year-old excavator operator with 20 years of mining experience, was fatally injured while loading haul trucks in a strip pit. The victim was operating a Komatsu PC 400 excavator, loading shot material from the active pit into a Komatsu 785 haul truck. A portion of the highwall collapsed onto the operator's compartment of the excavator, resulting in fatal injuries. The day before the accident, hazards were observed in the highwall by mine management, and afterward, mine management constructed an inadequate barricade to prevent access to the hazardous pit area. The hazards observed in the highwall and documented by mine management the day before the accident, were not reviewed by mine management the day of the accident. The hazards observed by mine management in the highwall during the pre-shift examination performed on the day of the accident, were not eliminated or mitigated by mine management.

1. Management did not ensure that proper blasting procedures were followed when blasting under high voltage power lines. Thirty-foot vertical holes were drilled and loaded heavily from 15 feet down to the bottom of the blast hole. This practice resulted in the bottom portion of the highwall being fractured while leaving the upper portion intact. As the shot materials were removed, the bottom portion of the highwall could not support the overlying rock structure, resulting in a toppling failure.

   Corrective action: Proper blasting procedures when blasting under or near high voltage power lines or towers were made part of the ground control plan.

2. Management did not ensure that the acknowledged ground control plan was being followed. Hazardous conditions were observed at the Redwine strip pit during the second shift by the bulldozer operator who reported the conditions to the foreman. The mine operator's ground control plan states: hazardous conditions will be corrected before the mining operation is allowed to proceed. If a hazardous highwall condition exists, the area will be posted to prevent personnel from entering the hazardous area."

   Corrective action: Proper posting procedures for hazardous conditions not corrected promptly were made part of the ground control plan.

3. The second shift foreman did not properly report an imminent danger condition, to the mine operator, when he identified the condition on the highwall in the Redwine pit, during an on-shift examination. The foreman recorded the information in the on-shift book, but did not verbally make the on-coming shift foreman or superintendent aware of the condition.

   Corrective action: The ground control plan has been amended to include the method of communication between shifts and to require the foreman of an on-coming shift to review the previous shift's on-shift record book prior to allowing work to commence in surface work areas.

4. Management failed to conduct an adequate examination of the highwall in the Redwine pit on the day of the accident, especially after heavy rains occurred in the area. The examination did not detect cracks and loose rocks that were obviously present in the highwall and miners were allowed to work in an unsafe area.

   Corrective action: The ground control plan has been amended to require additional examinations after every rain, freeze, or thaw prior to miners entering the pit area, and examinations shall be recorded in the daily record book.

5. Management assigned the excavator operator to work in close proximity to a hazardous highwall with the operator's compartment of the Komatsu PC 400 adjacent to the highwall. This placed the excavator operator in a dangerous location and prevented him from having any escape route when a portion of the highwall collapsed, crushing the operator's compartment.

   Corrective action: The ground control plan has been amended to prohibit excavators from working within fifty feet of a highwall.

6. Management failed to provide additional illumination for safe working conditions and to facilitate adequate examinations of work areas when operating in darkness. No light plant was used to illuminate the highwall and the work area in the pit. The superintendent performed an inspection of this pit prior to the start of day shift. The highwall inspection was performed in darkness without sufficient illumination. A mobile light plant was being stored at the mine.

   Corrective action: The ground control plan has been amended to require that portable light plants be used during hours worked in darkness.

Findings from MSHA's final investigation report, which supersedes the preliminary narrative above.

Activity at time of incident

Power Shovel, Dragline

Subunit / location

STRIP, QUARY, OPEN PIT

Accident type

Struck by falling object

Source of injury

CAVING ROCK,COAL,ORE,WSTE

Nature of injury

CRUSHING

Body part affected

MULTIPLE PARTS (MORE THAN ONE MAJOR)

Total mining experience

20 years

Experience at this mine

2 years

Experience in this job

2 years

Degree of injury

FATALITY