Crews responded to a report of a fire in the 2100 block of Willow Drive around 2 a.m., officials said.
By the time firefighters arrived, the two residents at the home had already evacuated the home, fire officials said.
One of the evacuated residents suffered smoke inhalation and was transported to Petaluma Valley Hospital. That resident is expected to survive, according to officials.
Three other residents of the home who were not there at the time of the fire, along with the two at the home, have received assistance by the American Red Cross for temporary housing.
A second alarm was called after crews arrived at the scene.
Crews were able to knock down the fire, but not before the home sustained major damage to the bedrooms and second story, officials said.
The fire remains under investigation.
