A brush fire in a rural area near San Diego Zoo Safari Park blackened about seven acres Tuesday, briefly posing an imminent structural threat but causing no reported structural damage or injuries. The blaze erupted shortly after 1 p.m. Tuesday off Highland Valley Road in Ramona, near Highland Tra ils Drive, according to Cal Fire. Ground crews and personnel aboard air tankers and water-dropping helicopters fought the fire, which moved dangerously close to a single structure, said Mike Cornette, a fire captain with the state agency. It was not immediately clear if it was a home or some other type of building that was threatened by the blaze. Firefighters had the spread of the flames halted by about 1:45 p.m., Cornette said. The cause of the fire was determined to be from a metal grinder, according to Cal Fire’s fire investigator. This story uses functionality that may not work in our app. Click here to open the story in your web browser. ...read more read less