Fire broke out inside Xcel Energy’s coal-fired power plant Monday morning in Burnsville, injuring one employee and briefly forcing about 50 others out of the facility, the company said.

The blaze began about 7:30 a.m. in a coal bunker at the Black Dog plant, according to a statement from the utility. The plant’s operations were unaffected, said company spokesman Tom Hoen.

Firefighters were on the scene at midday watching “for any flare ups or hot spots,” Hoen said.

There’s no immediate word on how the fire started in the plant, which sits on a strip of land just south of the Minnesota River and roughly halfway between the north-south corridors of Interstate 35W to the west and Hwy. 77 to the east.

The injured employee was taken to a hospital, the company said. Xcel had no immediate information on the seriousness of the injuries.

The other employees have been allowed back in, Xcel added.

The Black Dog plant was built in the 1950s as a coal-fired plant. Its Unit 1 boiler/turbine and Unit 2 boiler were replaced in 2000-2002 with a natural gas combined-cycle unit (Unit 5).

Units 3 and 4 are dual-fuel boilers (coal and natural gas) with steam turbines that will continue to use coal as the primary fuel until they are retired in April.