A US Mine Safety and Health Administration spokeswoman told ILN that the incident occurred about 10.50am local time, Tuesday at the Campbell County operation.

While she declined to identify the miners involved, the spokeswoman did confirm the trio was transported from a hospital to a burn center and are currently being treated for second- and third-degree burns.

“The ignition took place at a coal truck and crusher dump while a bearing was being changed on a chain conveyor,” MSHA said of the incident.

“The bottom hopper [crusher] doors had to be opened to access the conveyor, which allowed coal dust from a coal slide in the hopper to engulf the area.

“The dust was ignited by hot bearing embers and a weed burner used to heat the bearing race.”

A Peabody spokeswoman also confirmed the ignition to ILN but did not indicate the mine’s current operating status.

Both MSHA and Peabody are conducting investigations into the incident.

North Antelope Rochelle, located about 60 miles from Gillette, is the largest and most productive coal operation in North America.

The mine, which began operations in late 1983 and started production two years later, shipped 107.7 million tons of compliance coal last year.

North Antelope Rochelle extracts from the Wyodak-Anderson seam at a seam thickness range of 60 to 80 feet. It has shipped more than 1.8 billion tons since its production start.