Petaluma firefighters quickly extinguished a blaze Tuesday in a storage closet at an east Petaluma apartment complex.

Damage to the structure and its contents was estimated at $5,000, and no residents were displaced by the fire reported at the Baywood Apartments at 9:40 a.m., Battalion Chief Phil Sutsos said.

The cause of the blaze was not officially determined, but Sutsos said that a can of rags placed inside the closet may have been the fire's source.

The rags may have held some cleaning material that caused heat to build up, he said.

Petaluma rolled all fire units to the scene, initially reported as a house fire. Cal Fire, Rancho Adobe, Wilmar, San Antonio, Lakeville and Sonoma County fire departments assisted.