CLAYTON -- A Clayton home was badly damaged Saturday evening after a two-alarm fire engulfed much of the house in flames, fire officials said.

About 4:10 p.m., firefighters responded to the 300 block of Blue Oak Lane and found flames burning through the second story of the home, Contra Costa County Fire Battalion Chief Terry Buck said. Crews from Clayton, Concord, Walnut Creek and CalFire were called to the scene, and contained the blaze within the hour.

Fire officials determined the fire was started by a car in the garage, which the resident had seen smoking after returning from a drive, Buck said. The fire then spread throughout the garage, moving upwards into bedrooms and the attic.

The couple and their two cats managed to escape from the home unharmed, Buck said. No injuries were reported in the fire.

Damage to the home was estimated at about $200,000, Buck said. None of the adjacent homes were damaged or threatened by the fire.

Contact Erin Ivie at 925-847-2122. Follow her at Twitter.com/erin_ivie.