MARBLEHEAD – A slow-building fire crept through a chimney flue at a Marblehead home Thursday before it burst through a wall and caught the house on fire shortly after 5:30 p.m., firefighters said.Fire Captain Elizabeth Wilson said the couple who lives at 32 Beverly Ave. started a fire in the fireplace a few hours earlier but the situation got out of hand when the flames went through the chimney flue.”It breached the chimney and was in the wall on the first floor” when firefighters first arrived, Wilson said. “It burned for quite a while before it broke through. There was a lot of charring.”Wilson estimated the damages from the one-alarm fire at about $50,000.The occupants of the home, John and Joanne Nestor, both evacuated and no injuries were reported.Wilson said the couple had their chimney cleaned just two days ago.”This is a good reason to have your chimney inspected and not just cleaned,” Wilson said.She said frequently these types of fires happen at night.”They were lucky they were home and awake,” Wilson said.Salem and Swampscott fire departments provided mutual aid to Marblehead.