A man sleeping in a small city park in east Petaluma early Monday fell asleep with a cigarette in his mouth, igniting a fire, said a Petaluma fire official.
The flames caught the man's bedding, which spread to his bed of juniper bushes and then shot up a nearby palm tree, said Petaluma fire Battalion Chief Jeff Holden.
A Petaluma police officer on patrol spotted the fire at Sunset Park, a half-acre strip in front of the historic Sunset Line and Twine Co. building on Lakeville Street.
The officer also found Matthew Bylund, 44, sitting in bushes near the fire and got the man away from the flames. Bylund apparently wasn't injured.
Petaluma firefighters quickly put out the fire, which didn't spread beyond the park.
The officer arrested Bylund on suspicion of being drunk in public, obstructing an investigation and violating his probation. Police officials said Bylund initially gave officers false information.
One firefighter suffered a back injury while pulling hose for the effort, said Holden. The firefighter was taken to Petaluma Valley Hospital, treated and released.