A failing 4,160-volt circuit breaker caused an electrical arc that started a fire at a Tennessee Valley Authority coal-burning power plant on Wednesday.

Agency spokesman Jim Allen says the fire at the John Sevier Fossil Plant near Rogersville in East Tennessee occurred at around 2 p.m. Eastern. It was extinguished before 5 p.m., and no serious injuries were reported.

Two employees were treated for minor smoke inhalation.

The fire happened at one of the plant's four units, and Allen says TVA shut off the unit as a precaution.

He says a TVA fire brigade and police responded. They were assisted by emergency and ambulance units from Hawkins County.

According to TVA's Web site, the plant was built in 1957. It consumes about 5,700 tons of coal a day and generates 5 billion kilowatt-hours of electricity a year, enough to supply 350,000 homes.