The blaze erupted about 12:40 p.m. in the 200 block of South Earlham Street, according to the Orange Fire Department. Firefighters arrived to find downed power lines at the scene.
Three firefighters suffered electric shocks while battling the flames and were transported to a medical center, officials said.
A civilian was also hurt inside the home and was hospitalized. The nature of that person's injuries was unknown.
The cause of the incident is under investigation.