Through a parted crowd, the men of Engine Company 33 and Ladder Company 15 marched across City Hall Plaza in full gear, their eyes fixed straight ahead. In heavy, work-stained boots, they made their way to the stage, past the families of their fallen colleagues.
Two days after the deadly Beacon Street fire, the smell of smoke still clung to them.
His voice strained, Mayor Martin J. Walsh praised the heroism of Lieutenant Edward J. Walsh Jr., 43, and Firefighter Michael R. Kennedy, 33, who died Wednesday battling the wind-whipped blaze.
“Words cannot repay the debt of gratitude that we owe these men and their loved ones for the sacrifice they gave,” Walsh told the hushed crowd Friday. “But we must begin by acknowledging very clearly what it was that they did. They put themselves in harm’s way so that others might be safe.”
To the strains of “Amazing Grace,” the Fire Department’s red flag was slowly raised to half-staff.
As investigators continued the laborious process of determining the cause of the nine-alarm fire, the poignant ceremony spoke to its terrible cost, and a raw grief was felt across the city and beyond.
At a West Roxbury firehouse, a large crowd gathered in the rain to pay tribute.
And at the Boylston Street firehouse where Walsh and Kennedy worked, mourners came to pay their respects, resting flowers at a growing memorial. Many went inside to extend their condolences personally, and so many brought food that the station had more than it could ever use.
In the Back Bay, one lane of traffic on Beacon Street in front of the buildng remained closed as specialists examined the scene of the fast-moving fire, which trapped the firefighters in the basement of the four-story brick building, and Boston police investigators canvassed the neighborhood to ask residents if they saw anything unusual before the fire broke out.
Steve MacDonald, a spokesman for the city’s Fire Department, said it would probably take investigators weeks to complete their task.
“It’s going to be slow and methodical,” he said. “It’s a drawn-out process.”
Authorities say the blaze appeared to have started in the basement, and investigators are focusing on the building’s oil furnace and heating system as potential causes.
Investigators will begin by analyzing burn patterns and ruling out causes, MacDonald said.
They will interview scores of witnesses, including firefighters, neighbors who were home at the time of the fire, and everyone who lived in the building.
Frances X. Hogan, whose firm represents the executor of the estate that owns the 298 Beacon St. property, said fire investigators spent hours Friday combing through the wreckage.
“They were there all day,” she said. Hogan has said the property was well maintained, but she declined to say how old the furnace was or when it was last serviced.
Franklin Knotts, the property manager, could not be reached for comment Friday.
The building is owned by the estate of Michael J. Callahan, who lived there until he died in 2002 at age 85, public records show.
Documents filed in Suffolk Probate and Family Court indicate that the estate spent about $3,000 on repairs for the building, including some minor electrical work, from Nov. 11, 2012 through Nov. 11, 2013. It also spent about $5,200 on cleaning services, $9,820 for property management services, and $1,300 on fire alarm services.
The estate spent tens of thousands more for administrative and legal fees. The executor, Herbert S. Lerman, received $3,772, while his law firm, Lyne Woodworth & Evarts LLP in Boston, received about $59,000 for legal work on the estate and in Suffolk Superior Court.
Some residents of the apartment building returned to their lost home Friday, surveying the destruction from across the street.
Two former tenants, who declined to be quoted by name, said they escaped the fire through a window, climbing onto a fire escape and down a narrow ladder to safety.
The tenants said they were deeply saddened by the firefighters’ deaths.
“It’s just an awful situation,” said one. “They are the heroes, and they risk their lives to save others.”
The two tenants described the apartment building as clean, safe, and problem-free.
While the fire caused extensive damage, including a collapsed roof, a city building inspector said the building can be salvaged.
“The main exterior walls have not collapsed at all,” said David Johnson, the inspector. “It was able to stand up to the fire, so it’s still intact.”
A structural engineer assessed the building Friday to determine its integrity, he said.
Still, the scope of the damage will make the scene harder to analyze, and MacDonald acknowledged that investigators cannot always pinpoint a fire’s cause.
“We do have fires that go undetermined,” he said, “especially if it’s a heavy volume of fire and everything is burnt away.”
Walsh and Kennedy had entered the basement to battle the fire at its source, but they were pinned down when the blaze rapidly intensified. Officials have said that a broken window caused a backdraft that overwhelmed the men, who pleaded for more water as they tried to fend off the flames. Some firefighters have speculated that the hose the men were using burned through, leaving them defenseless.
MacDonald said the city’s fire commissioner will eventually convene a board of inquiry to study what happened and determine whether changes in fire operations should be made. The committee typically includes several fire officials and specialists, such as structural engineers and medical examiners.
The last such report was issued in March 2009, two months after a firetruck crash in Mission Hill that killed Lieutenant Kevin M. Kelley. The panel determined that the brake failure that led to the crash was caused in part by inadequate maintenance.
Amid an outpouring of public support for the city’s firefighters, officials have set up a fund for the families of Walsh and Kennedy. Donations can be made at bosfirecu.com .
“I guess our goal is to relieve the stress a little bit for the families,” said Edward Kelly, president of the Professional Fire Fighters of Massachusetts.
On Friday, a witness recalled encountering Walsh just before he responded to the fire at 298 Beacon St., when he and two other firefighters went to a nearby building to check out a fire alarm.
“When he came through the door he was just so huge,” said Ronny MacDonald, who is part of a crew renovating the third floor at 274 Beacon St., where the fire alarm was accidentally tripped shortly before the fatal fire.
“I was looking at his eyes and going, ‘Oh, my God, this guy’s a giant,’ ” MacDonald said. “I mean, he filled up that whole hallway. I was just starstruck, you know, when you see the guy.”
The firefighters checked out the building, found that nothing was amiss, and left, said MacDonald. “Shortly after is when we heard all the sirens,” he said.
Also on Friday, funeral arrangements for the firefighters were announced. Walsh’s funeral Mass will be said at 10:30 a.m. Wednesday in St. Patrick’s Church in Watertown. Visiting hours will be from 3 to 8 p.m. Tuesday at the church.
Kennedy’s funeral Mass will be said at 11 a.m. Thursday in Holy Name Church in West Roxbury. Burial will be in Forest Hills Cemetery. Visiting hours will be 4 to 8 p.m. Wednesday in P.E. Murray-F.J. Higgins, George F. Doherty & Sons Funeral Home in West Roxbury.
At the vigil in West Roxbury Friday, many held US flags or candles, and wreaths were laid under two memorial plaques for Paul J. Cahill and Warren J. Payne, Boston firefighters killed in the line of duty in 2007.
Some of Kennedy’s relatives attended the vigil, and embraced several people who offered condolences. An emergency call came in during the event and two firetrucks raced out of the station, drawing cheers from the crowd.
Several hundred people packed Holy Name Church for a second vigil, attended by the firefighters’ families and several elected officials, including Mayor Walsh.
The Rev. George F. Carlson, the pastor, told the hushed congregation that he had baptized Lieutenant Walsh. Carlson said that when he first learned of the tragedy, “What came flooding back? Memories, memories.”
He urged those in attendance to share stories of both men during their time of grief.
“How do we mourn those we love?” Carlson asked. “We remember.”
Outside the vigil, Pat Londergan, 62, said she was heartened by the outpouring of support for the families of the two men. “Just to be here is a wonderful thing,” said Londergan, a Norwood resident who grew up in West Roxbury and whose father was a Boston firefighter.
Councilor Tito Jackson said outside the church that the community must help everyone affected by the deaths of Kennedy and Walsh.
“I think we have a hard week ahead of us, laying these two heroes to rest,” he said.Travis Andersen, Todd Wallack, Andrew Ryan, Martin Finucane, and Laura Crimaldi of the Globe staff contributed to this report.