The agency confirmed the inspection blitz and said it was prompted by a recent incident involving a burning belt at Alpha’s Road Fork No. 51 mine in Wyoming County, W.Va., which was also once owned by Massey.

In an SEC filing, Alpha said the incident at Road Fork No. 51 mine on May 18 involved smoke generated by “a slipping conveyor belt.” MSHA considered the situation so threatening that it issued an imminent danger order, forcing evacuation of that section of the mine. Alpha said no fire was discovered and no injuries resulted.