Authorities said a late-August grass fire in the rural Two Rock area west of Petaluma was put out before it could cause damage to structures — with some help from locals.

“Our first unit arrived within four minutes of dispatch to find some local residents attempting to extinguish the fire with hand tools,” said Darrin DeCarli, deputy chief at the Gold Ridge Fire District.

Named the Rock Fire, it was first reported at approximately 1:50 p.m. on Aug. 27 in the area of Middle Two Rock Road and Eastman Lane.

The fire was fully contained within an hour and burned about three quarters of an acre of vegetation. No structures were damaged and no injuries were reported. The cause of the fire remains under investigation.

Agencies assisting in the fire included the Gold Ridge Fire Protection District, the Petaluma Fire Department, Rancho Adobe Fire, Coast Guard Fire Department and Cal Fire.

Amelia Richardson is a staff writer for the Argus-Courier. She can be reached at amelia.richardson@arguscourier.com or 707-521-5208.