Xcel Energy's Black Dog coal power plant in Burnsville was shut down Tuesday after a small explosion and fire.
Xcel spokesman Thomas Hoen said officials noticed smoldering in one of the coal units and called the Burnsville Fire Department. While on scene, a small explosion occurred in the unit, causing a fire.
Firefighters were still battling the blaze late Tuesday morning.
Two firefighters were treated for minor injuries at the scene, and a third was taken to the hospital with a twisted knee or ankle. No one else was injured.
Hoen said officials will try to assess damage to the plant. As a precaution, all three units of the plant have been shut down.
Hoen said it wasn't yet clear when the plant would be up and running again.
Authorities have closed nearby ramps along Interstate 35W to deal with traffic in the area.
The Black Dog plant generates about 540 megawatts of power using coal and natural gas. It's located on the Minnesota River.