Continuous miner operator Elam Jones, 29, died March 22 at Rhino Resource Partners’ Castle Valley No. 4 operation near Huntington. He was operating a remote-controlled CM during retreat mining when a rock fell while.

“While mining a left-hand lift, the victim and his helper were positioned near the right rear corner of the continuous mining machine and the right rib,” US Mine Safety and Health Administration investigators said in their preliminary findings from the incident.

The section of roof that hit the nine-year mining veteran measured about 8x7feet and was 16 inches thick. Several roof bolts were broken in the fall, officials said.

The fallen rock also injured the victim’s helper, though that miner was treated at a local medical facility and released.

That individual’s name was not confirmed by the agency.

MSHA said the rock slab was a portion of a larger fall, roughly 20 feet wide by 25 feet long, that included the bolted roof between the rear of the continuous mining machine and the mobile roof support units located inby.

In an effort to prevent similar incidents at other mines in the nation, investigators issued a series of best practices. These include a reminder for all operators to ensure their approved roof control plan support provisions are being followed and that the outlines are suitable for current geological conditions.

It also stressed the development of a map of geologic features so additional support can focus on those areas.

“Conduct frequent and adequate examinations of roof, face, and ribs,” MSHA said.

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

Other best practices include maintaining proper entry widths and pillar dimensions, developing a safe procedure to align mobile roof supports with the lift being mined and the regular installation and examination of test holes to look for changes in roof strata.

Finally, the agency reminded mines to take additional steps when hazards associated with draw rock are encountered, such as mining shorter cuts and decreasing roof bolt spacing and, when joints are encountered, to install adequate supplemental supports.

Jones was the eighth coal miner killed in the US in 2013, and the second worker to die from a fall of face, rib or highwall incident this year.

According to federal data, Castle Valley produced just under 1 million tons in 2012, with about 146,000 man hours worked. It recorded one non-fatal day lost to injury last year.