A three-alarm fire sparked by a short-circuited radiant floor heater caused more than $5 million in damage Wednesday morning to a posh three-unit condominium building on Commonwealth Avenue near Boston’s Public Garden.
“I’d say more than anything here the loss of any property or furniture isn’t really that important,” said John Walsh, the owner and chief executive of the Elizabeth Grady salon and spa chain, who was taking a shower inside his third-floor condominium when he heard the fire alarm blaring at about 9:18 a.m.
When told about the damage estimate to the five-story brick brownstone at 17 Commonwealth Ave., he said, “I’m sure it exceeds that.”
There were no injuries. Five people live in the building, but only Walsh was inside. He said he customarily stays at his condo only on weekends, but happened to have stayed overnight.
There were some harrowing moments for two early-arriving firefighters who immediately headed to the roof to cut a hole to allow the heavy smoke to escape.
One firefighter walked up the stairs and the other rode a ladder to the roof. Less than a minute later, things turned “nasty” according to Boston Fire Department spokesman Steve MacDonald. The firefighters decided that conditions were too dire to stay on the roof and, sensing that they wouldn’t be able to reach an aerial ladder nearby, they broke through a circular window at 19 Commonwealth and climbed in head-first.
The firefighters walked downstairs and back into 17 Commonwealth to continue fighting the fire.
“I wouldn’t say I was scared by any means; I was just grateful that these firefighters knew what they were doing,” said Walsh, who has owned the condo for three years. “They were absolutely all over it. It was flawless. It was admirable, so efficient.”
The fire was initially reported to be in the ductwork in the fourth-floor ceiling, fire officials said. Firefighters opened the ceiling to get at the fire, and investigators later discovered the source of the blaze, a floor heater mounted to the fourth-floor ceiling that is regulated by a thermostat. The fire spread along the fifth floor and then up through the walls, fire officials said.
Construction workers rehabilitating 15 Commonwealth Ave. noticed smoke coming from the fourth and fifth floors of 17 Commonwealth and alerted a firefighter working on detail at the construction site.
A total of 30 construction workers walked out the front of the building under rehabilitation. There is a brick firewall between the two properties, and officials said the construction had nothing to do with the start of the fire.
Much of the damage to 17 Commonwealth Ave. was from the water used to douse the blaze, officials said. Authorities described the water at one point cascading off an elaborate chandelier.
Walsh said he put on sweat clothes, walked downstairs to the fire alarm box, and saw that the fire panel had lit for the fourth and fifth floors, indicating the location of the fire.
Walsh said he called the property management, but firefighters were already arriving. The building’s fire alarm system is connected to a monitoring service that immediately alerts the department when fire is detected.
The owner of the fourth and fifth floors, the most heavily damaged area, is on vacation in Hawaii.
There was a “structural collapse” on the fourth floor, fire officials said.
The blaze drew dozens of spectators, most of whom stood on the paved path that cuts through the green space of the Commonwealth Avenue Mall, one of the more popular strolling destinations in the city.
The three units comprise a total of 8,241 square feet assessed at $7,041,800. The structure was built in 1900, according to city records.Brian Ballou can be reached at firstname.lastname@example.org. Follow him on Twitter @GlobeBallou.