HEALDSBURG -- Fire investigators are estimating that a three-alarm fire that ignited at an elementary school near Healdsburg Sunday morning caused about $500,000 damage.

Firefighters were dispatched at 6:18 a.m. to West Side Elementary School, located at 1201 Felta Road in unincorporated Sonoma County, Sonoma Fire Chief Vern Losh said. Firefighters from 11 fire districts responded to the call and the flames were knocked down at around 7 a.m.

The fire was declared under control by 8 a.m.

The fire completely burned one classroom, the administrative offices, a janitor's room, four bathrooms and an auditorium, Losh said. The library suffered moderate smoke damage, but most of the books and other contents were saved. Firefighters will be at the school throughout the day cleaning up debris and putting out hot spots.

There is a limited supply of water near the rural school, so water tenders were called to the scene to assist, according to Losh.

"We were able to save a significant portion of the school because of the excellent mutual aid and cooperation displayed by our fire agencies," Losh said. "This fire in a rural setting with a limited water supply could have burned out of control, but everyone deployed rapidly and we were able to control it quickly."

The school buildings were not equipped with a fire sprinkler system, according to the Healdsburg Fire Department.