http://www.sltrib.com/news/ci_7059509<snip>
The retreat mining plan was approved in February, and work progressed until March, when a major bump - where pressures in the mine cause coal to burst from the roof or pillars - significantly damaged the mine and prompted operators to abandon efforts to recover the pillars in the north barrier.
Stricklin says the bump was not officially reported to MSHA; the company maintains it didn't have to report the event. The MSHA investigation will consider whether the event should have been reported, Stricklin said.
Despite the problems retreat mining in the north barrier, when mine operators asked MSHA to approve a similar plan in the south barrier, it was quickly OK'd on June 15.
Robert Ferriter, director of the Mine Safety and Health Program at the Colorado School of Mines, said that, given the problems that were experienced in the north barrier and the similarities in the type of mining and conditions, "one could reasonably anticipate the occurrence of additional coal mine bumps.
"The risk was quite clear," Ferriter said in his prepared testimony.
Ferriter quotes several reports by a Bureau of Land Management inspector, noting deteriorating conditions, bumps and roof falls in the area being mined.