Crew leader Joseph Cassell, 33, was working at the No. 4 South section of Rhino Eastern’s Eagle No. 1 operation in Raleigh County preparing to set timbers on June 27 when he was killed in a rib roll incident.

The rib brow that fell and crushed him at about 1am local time measured 100 inches in height by 32 feet in width by 37in in thickness.

To avoid similar incidents in the future at other US operations, the agency compiled best practices for mines, including the visual examination of the mine’s roof, face and ribs immediately before any work or travel in an area.

MSHA also stresses the need to perform careful examinations of pillar corners, particularly when angles are formed between entries and crosscuts that are less than 90 degrees.

Before beginning any work, miners must scale or support any loose rib or roof material, and additional precautions should be taken as mining heights increase to keep rib hazards from developing. If an area is prone to deterioration, the operator should install rib support upon initial mining in the area.

Finally, crews should be alert to changing geologic conditions that can impact roof and rib conditions.

Federal officials encourage anyone with additional prevention ideas to submit them through its web site, including the year of the fatality and the fatality number.

Cassell’s death is the seventh in the industry in the 2011 calendar year and the first classified by MSHA under fall of face/rib/highwall.