According to the agency’s historical data, 80% of roof fall injuries occur under supported roof, and there are more incidents in that classification in summer than at any other time of the year.

Those sobering statistics lent themselves to the theme for this year’s PROP campaign, "Just because it's supported doesn't mean it's safe".

Agency officials noted roof falls are more prevalent in the US summer because of the warm air carried into the mine from the hot, humid outside environment.

That moisture is subsequently absorbed into roof strata, causing weakness and the potential for a fall.

"A mine's roof control plan specifies the minimum roof support required under normal conditions, but those minimum requirements no longer apply when adverse conditions are encountered," MSHA deputy assistant secretary for operations Michael Davis said.

During the program, which began on June 1 and will run until September 30, federal inspectors will present roof fall and rib roll danger information directly to mines and workers, and will also distribute information packs with guidelines on controlling the issues.

Staff will also outline the importance of consistent, thorough mine examinations.

Because the installation of wire mesh in bolted areas can help prevent injuries when rock falls occur between bolts, inspectors will advise miners and operators to decrease bolt spacing and consider the use of the mesh product.

The agency pointed out that using shorter cut depths can allow the roof to be bolted sooner, and help prevent sag as well as roof strata separation that can lead to roof falls.

Any US operation can visit the MSHA website at any time for a list of best practices to address ground control for a deep cover operation.

A printable poster on PROP is also available there.