An off-duty firefighter spotted smoke at an eastside Petaluma home Sunday evening and went into the home to alert residents their home was afire.
The 5:32 p.m. fire apparently started in the garage of the Tampico Court home, said Petaluma Battalion Chief Phil Sutsos.
Santa Rosa firefighter Tony Camilleri was driving in the area while headed to dinner with his wife when he saw the smoke and went to investigate, said Santa Rosa Battalion Chief Mike Jones.
Camilleri found the garage on fire and the house darkened from a loss of power. There were no firefighters yet on scene.
Neighbors said they thought there were people inside and the firefighter went into the home and made sure an adult and two children got out safely.
Petaluma firefighters, stationed just blocks away on McDowell Boulevard, got there within four minutes, according to dispatch records.
They found flames coming from the garage of the two-story home.
Cal Fire and Rancho Adobe firefighters helped fight the blaze. Firefighters had it under control in about 20 minutes and were at the house until about 9:15 p.m. to finish the job, Sutsos said.
Everything in the garage appeared to be lost, including a 1970s Cadillac. Heavy smoke and heat also damaged the attached house.
Sutsos estimated the fire caused as much as $200,000 damage.
Because all of Petaluma's on-duty firefighters were called to the fire, Wilmar, San Antonio and Lakeville firefighters came into Petaluma to cover Petaluma's stations in case of other calls for help.
The visiting firefighters handled three calls for service.
The cause of the fire remained under investigation Monday.