Firefighters were busy overnight with a vacant house fire that also with sparked two separate brush fires on the same property.
The blaze started at about 2 a.m. on Wednesday in a vacant home on West Petaluma Boulevard, which is near Pleasanton Road on the south side.
The house is in the middle of a field and the fire spread to the grass around the home.
Firefighters were able to extinguish all fires.
Crews say there have been two previous attempts to set this house on fire this year.
Arson is now investigating whether it was intentionally set.