Section Foreman

An EE was fatally injured when coal and rock material fell from the mine rib while rib bolting, and pinned the injured against the continuous mining machine. The rock and coal material measured approximately 6.3'x3.2'x2.0'. The miner was trained in the task being performed.

On Wednesday, June 2, 2021, at approximately 2:10 a.m., Trenten J. Dille, a 25-year-old section foreman, died when a portion of the mine rib sheared off and pinned him against a continuous mining machine while he was attempting to install a rib bolt. The accident occurred because the mine operator: 1) did not perform an adequate evaluation of the hazardous rib conditions to determine the safest corrective action; and 2) did not have effective policies or procedures to adequately support or otherwise control mine rib corners before the continuous mining machine had advanced enough to install rib bolts.

1. The mine operator did not perform an adequate evaluation of the changing rib conditions to determine the safest action to correct the hazard.

   Corrective action: The mine operator modified their written training materials to include the various corrective actions available to address hazardous rib conditions. The mine operator trained all affected miners in scaling methods, bolting techniques, and machine capabilities for correcting hazardous rib conditions. In addition, evaluating the location, type of rib hazard, and correct body positioning to limit exposure was also included in the training.

2. The mine operator did not have effective policies or procedures to adequately support or control the mine rib corners before the continuous mining machine had advanced enough to install rib bolts.

   Corrective action: The mine operator developed new policies and procedures and revised the roof control plan to install two additional rib bolts in the upper portion of ribs to support locations that will become rib corners. In areas where the mine operator cannot install additional rib bolts, the mine operator will cut the rib corners before the miners are exposed to the corner.

Read the full report (PDF)

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

Activity at time of incident

Roof Bolter, Nec

Subunit / location

UNDERGROUND

Underground location

FACE

Mining method

Continuous Mining

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

5 years

Experience at this mine

3 years

Experience in this job

1 year

Degree of injury

FATALITY