Fire investigators Tuesday tried to pinpoint what started a five-acre Cotati area blaze that destroyed three homes and displaced three families.
It could have been started by a car backfire, as some people reported, or fallen power lines or other possibilities Tuesday's team of investigators were trying to narrow down, said Cal Fire Division Chief Eric Hoffmann.
The fire started on the south side of Highway 116, near Stony Point Road. It quickly jumped the highway, caught the dry grass on the north side and spread to the nearby homes.
A Rancho Adobe fire engine from downtown Cotati arrived within six minutes of the 4:06 p.m. dispatch Monday.
Battalion Chief Herb Wandel immediately called for a second alarm, wanting more help and more water because of threatened property and the potential for the fire to burn across the dry fields.