Petaluma Police responded to a report of arson early Saturday on the 1000 block of Aspen Way.
Police said that homeowners awoke to the smell of smoke and when they opened their front door they found the "welcome" door mat on fire with "what appeared to be a flammable liquid."
The flames caused damage to the mat and the trim on the door.
This case of the fire is under investigation. Anyone with information regarding this case is asked to call the Department at 707-778-4373 and refer to report number 14-0468.