The incident occurred last month during the removal of an overburden where two openings into an abandoned underground coal mine were revealed.
At the time, workers continued for the remainder of the shift. The next day a MSHA inspector visited the mine when no workers were present and drove into the pit where his vehicle stalled and could not be re-started.
When the inspector exited the vehicle, he became light-headed and experienced tightness in his chest. He was able to walk out of the pit and phone for help.
An investigation of the area was conducted where oxygen levels were found to be as low as 9.3%.
In response to this incident the MSHA issued a number of suggested policies for miners to follow if old mine openings are encountered. The department said to stop all work and contact a qualified person to examine the area before any further work takes place. Record results of the examination, including all hazards identified.
If hazardous conditions are found, evacuate all persons until the conditions have been corrected and as soon as practicable after discovery, back fill mine openings encountered.
The MSHA also advised operations to develop a plan that addressed examinations for gases, under what conditions to evacuate, and procedures to follow to correct the conditions when (surface) mining near known abandoned underground workings.