A fire driven by strong winds raced through a brownstone on Wednesday, trapping and killing two firefighters in the basement, where their colleagues could not rescue them.
Thirteen other firefighters were injured in the blaze, and several police officers also were taken to hospitals. Some residents had to be rescued from the upper floors of the four-story apartment building, but none was hurt, city officials said.
"Today's a sad day for the city of Boston," Mayor Marty Walsh said. "We lost two heroes here today."
The firefighters were identified as Lt. Edward J. Walsh, a 43-year-old father of three who had almost a decade of experience, and firefighter Michael R. Kennedy, a 33-year-old Marine Corps combat veteran who had been a firefighter for more than six years.
Deputy Fire Chief Joseph Finn said the fire, which sent smoke and flames pouring from the roof and windows of the brownstone, appeared to have started in the basement but moved quickly throughout the building. The cause wasn't known, but he said all indications are that it was accidental and that it was the wind that caused the fire to spread through the building so quickly. Firewalls stopped the fire from consuming adjacent buildings.
"In 30 years I've never seen a fire travel that fast, escalate that quickly and create such havoc in such a short period of time," Finn said.
He said Walsh and Kennedy had gone down inside stairs into the basement, and he assumed that a front window broke out and blew the fire back at them. They called a mayday within two or three minutes of entering the building.
Kennedy was found about 30 minutes later and was pulled from the building but was pronounced dead at a hospital. Walsh's body was recovered later and was removed in what fire department spokesman Steve MacDonald described as "a very solemn ceremony," in which he was carried on a stretcher out the back of the building through a line of saluting firefighters.
Some of the other firefighters were injured when they were blown down stairs by a backdraft explosion caused by the wind, Finn said.
The fire snarled traffic in the city's densely populated Back Bay neighbourhood. Major thoroughfare Storrow Drive was shut down for a time, and people were asked to stay out of the area until Thursday morning. The mayor's office designated the nearby Boston Public Library as a centre for people displaced or otherwise affected by the fire to get help.
Despite 30 mph winds that gusted to 45 mph and cold temperatures, people gathered to watch firefighters work from outside the building, which was still burning Wednesday night.
"The smoke was unbelievable," said Kayla Dasilva, who lives a few blocks away and went with her roommate to see what was happening.
Anna Kosmidou, who lives in the apartment building next to the one that caught fire, said she and other residents were told they could not stay there Wednesday night.
"I'm very, very afraid. I'm still in shock," she said. "They called me at work, and then I ran over here."
The last Boston firefighter killed on duty died in 2009, when the fire truck in which he was riding struck a building after its brakes failed. Two firefighters died in 2007 battling a restaurant fire in the West Roxbury neighbourhood.
At Engine 33/Ladder 15, Kennedy and Walsh's station, not far from the fire and in the shadow of the Prudential Center, people stopped by to pay their respects.
Ralph Watson, a middle school principal in Cambridge, left a bouquet of roses outside the station.
"We live just down from where the fire was. It's very sad," he said. "We were standing when they took, I think, one of them by in a stretcher."
Expressions of condolences came from around the state, including from New England Patriots quarterback Tom Brady, who lives in Back Bay.
"On behalf of my entire family, I want to extend my deepest sympathies and condolences to the Boston Fire Department and the families of our brave and selfless firefighters who gave their lives for our protection and safety today, and to the entire firefighting community who protect us each and every day," Brady said. "All of you will be in our thoughts and prayers."