The U.S. Mine Safety and Health Administration just issued its report on that roof collapse that killed two workers in April at Alliance Resource Partners’ Dotiki Mine in Hopkins County, Ky.

You can read the full report here, but this is the text of the citation issued by MSHA inspectors after their investigation:

The roof was not adequately supported or otherwise controlled to protect persons from hazards related to falls of the roof. On April 28, 2010, two miners received fatal injuries from a roof fall in the face area of the No. 3 Entry, inby Crosscut 25, on the No. 6 Working Section, 2nd SE Panel off 2nd NE Sub-Mains. The unsupported area above the deep cut allowed the overlying roof that was weakened by slickensides (slips) to break the layers of strata. A massive section of roof, up to 76 feet long, 19 feet wide, and a maximum 10 feet thick, fell on the area that included the two miners and the continuous mining machine. Ten rows of bolts were disturbed (pulled out) because of the roof fall. Overburden across the face area inby the feeder ranges from 875 to 900 feet. Reportedly, no supplemental support had been installed in the roof fall area. The roof support was installed according to the approved roof control plan. This citation is being issued as enforcement action based upon the fatal accident investigation.

While the company’s MSHA-approved roof control plan was apparently being followed at the time of the accident, federal inspectors concluded:

The mine operator failed to detect the presence of slickensides, which dismembered the overlying shale and sandy shale beds and caused the roof to fall.

Killed in this tragedy were Michael W. Carter, a continuous mining machine helper with 2 years mining experience, and Justin W. Travis, a continuing mining machine operator with 3 1/2 years experience.

Previous posts about this accident are available here, here and here.