In December 1984 the mine employed 326 miners, and 290 of those were working underground on three shifts-a-day, five days a week.
The Wilberg Mine is most notable for the fire on 19 December 1984, which claimed 27 lives: 18 miners and 9 company officials.
The escape route of the 27 persons was cut off when the fire quickly engulfed the intake of the 5th Right longwall.
The fire was caused by a faulty air compressor, which was allowed to run unattended in an area that was not fire-proofed.
[2] In his article, "Remembering Wilberg, the lives lost, the humanity found" in The Salt Lake Tribune, Mike Gorrell says: "Mine Safety and Health Administration (MSHA) investigators determined an air compressor with two defective safety devices was turned on accidentally and left running unattended for 69 hours before self-combusting, its flames filling mine tunnels with poisonous gases.