Twenty-four firefighters responded to the blaze at 346 Steele Lane in west Santa Rosa around 8:20 p.m.
Windows on the side of the single-story house were shattering from the high heat and flames, which were threatening an adjoining single-family house soon after firefighters arrived, Battalion Chief Mike Jones said.
Firefighters contained the flames to two rooms and a kitchen but the rest of the house sustained heat, smoke and water damage, Jones said.
The fire was kept out of the main living room and bedrooms and firefighters salvaged many of the occupants' personal belongings, Jones said.
An occupant of the house escaped safely, but one cat died, one is missing and one had to be resuscitated, according to Jones.
Property damage from the blaze is estimated at $10,000 and structural damage is $50,000, Jones said.
The Rincon Valley Fire Department also responded to the fire, which was located near Steele Lane Elementary School.