The state fire marshal’s office has determined Tuesday’s early-morning fire in Somerville was electrical, starting in a light fixture in the living room ceiling in the first-floor apartment at 19 Banks St.
The three-alarm fire, which was investigated by the Somerville Fire Department, is not part of a string of five fires of suspicious origin in the city that are under investigation, according to Jennifer Mieth, spokeswoman for the fire marshal.
Tuesday’s electrical fire broke out about 5 a.m. and spread into neighboring 17 Banks St., causing significant damage to both two-family homes, fire officials said. Eight people were inside the homes and all were able to get out unharmed, Somerville District Fire Chief Frank Lee said.
Seven fires have broken out in Somerville homes in the early-morning hours since July 12, including one July 25 that ripped through multiple homes on Calvin Street and Beacon Place, displacing 45 people. That blaze is among the five that remain under investigation by a team of state and local investigators, Deputy Fire Chief Patrick Sullivan said Tuesday.
The electrical fire spread through a first-floor window at 19 Banks St. onto cars parked in a driveway tightly fit between the two homes, and traveled through all three floors of 17 Banks St., fire officials said.
Five of the seven fires are of suspicious origin. They are being investigated by the state’s fire marshal office.
The fire was contained quickly, but it took fire crews several hours to put out hot spots in the roof of 17 Banks St., Lee said. Ten engines, four ladder trucks, and one other vehicle responded to the fire, with companies from Boston, Cambridge, Medford, and Everett providing assistance.
The damage was limited to the two homes and the cars parked in the driveway. Lee said 19 Banks St. sustained about $300,000 in damage, and 17 Banks St. at least $500,000.