PHOTOS: Firefighters are investigating the cause of a fire that damaged the rear exterior of 18 Greystone St. on Monday afternoon. Firefighters were called by a neighbor who said she smelled smoke and went outside and saw flames creeping up the side of a house across the street. No one was inside the house when firefighters arrived at about 4 p.m., Quincy Deputy Fire Chief Timothy Burchill said. It took 5 minutes for firefighters to put out the flames. The fire started outside the house and caused between $25,000 and $30,000 in damage, Burchill said.