Commercial building fire extinguished by sprinkler system (Santa Rosa, CA)

Firefighters responded to a fire at a commercial building in Santa Rosa on Monday night that was related to a marijuana grow operation, fire officials said.  The fire had burned in a room that contained a marijuana grow, but the flames had been extinguished by a single sprinkler head, according to the fire department.  A fire investigator determined the fire was sparked by misuse of electrical equipment by the tenants.