Continuous mining machine operator Lenny Gilliam, 56, died August 6 at Arch Coal’s Lone Mountain Processing Huff Creek No. 1 underground operation in eastern Kentucky following a coal rib outburst.

The US Mine Safety and Health Administration said in its preliminary findings from the Harlan County event that the section crew was retreat mining at the time in the mine’s first right lift of the No. 3 entry in a five-entry system.

Two other miners were injured, one of them seriously. They were identified as Terry Scott and Johnny Nantz.

In an effort to prevent future similar incidents at other mines, MSHA has asked operators to ensure the support provisions of their respective approved roof control plans are suitable for the mine’s geological conditions and the plan is being followed.

Roof and rib control methods should be adequate for the depth of cover and for the potential effects of any mines above or below active workings.

The agency is also urging the development of a map indicating geological features and anomalies to determine orientation as a means to predict when and where they could be encountered during mining. This also permits the use of additional roof support that can focus on those areas.

MSHA is asking mines to maintain proper entry widths and pillar dimensions, and conduct frequent and adequate examinations of the mine’s roof, face and ribs.

“Be alert for changing conditions,” investigators said.

“When hazardous conditions are detected, danger off access to the area until it is made safe for work and travel.”

Federal officials said that, when gob falls have been delayed for periods exceeding routine intervals for current mining conditions, the area should be completely evaluated and the operator should consider evacuating miners and equipment to a safe area until the fall occurs.

Gilliam’s death was the 12th in coal in 2013, the second in Kentucky, and the first this year to be classified to be fall of face, rib or highwall.

The fatal accident at Huff Creek was also the mine’s fourth in 11 years. Two miners died there in 2002 and a single death was recorded in 2006.

Its non-fatal days lost rate has been consistently below the national average over that period.

According to federal data, an MSHA inspection at the 124-worker mine that has been ongoing since July 1 has so far resulted in 13 alleged violations. Some of those have been for roof control violations.

Huff Creek was idle for the federal, state and internal investigations.

Its operating status Tuesday was active, according to federal data.