Cambridge Fire Chief Gerald Reardon said that the fire likely began after midnight in the first or second floor of 1110 Mass. Ave., near Arrow Street.
He said flames probably climbed through a pipe chase—the area between the inner and outer wall where heating and water pipes go from floor to floor—to the upper floors.
Nine Cambridge Fire vehicles and several ambulances responded to the scene as well as Cambridge Police, who blocked the thoroughfare to traffic.
Firefighters broke the building’s windows and cut a hole in the roof with a chainsaw to vent smoke as they doused the flames and searched the building.
The wood-frame building contains five units, of which four are commercial and one is residential. None of the units was occupied at the time of the fire.
The building houses The Attic Gallery shop—“a collection of rare finds” including designer timepieces and other trinkets—on the first floor, garden decoration gift shop Gnome and Rose on the second floor and Frank Shirley Architects on the third floor.
Frigid temperatures didn’t stop passers-by from gathering along the sidewalk across the street to watch the spectacle, which, walking down Mass. Ave., was hard to miss.
Hoses crisscrossed the ground, and smoke swirled in the air until about 2 a.m., when the air cleared and damage to the building was assessed.
Reardon said he could not speculate on the cause of the fire, but added that it is under investigation by the Cambridge Fire Investigation Unit.
Rory A. O’Connor of Cambridge, the owner of the building, said that the cause may have been a heating malfunction in the top-floor apartment.
According to O’Connor, the damage may take anywhere from six to eight months to repair.
“There’s pretty good damage from bottom to top,” O’Connor said.
O’Connor said that he didn’t know who reported the fire, but joked, “they must have been driving the wrong way on Mass. Ave. to see it,” as the flames were only visible from the side of the building nearest to Harvard Square.