A team of four federal investigators will be looking for answers in the Back Bay blaze late last month that killed two Boston firefighters.
The National Institute for Occupational Safety and Health, also called NIOSH, which has investigated two other fatal firefighting incidents in Boston in recent years, announced Friday that it would look into the deaths of Lieutenant Edward J. Walsh Jr., 43, and firefighter Michael R. Kennedy, 33.
“The NIOSH program is intended to identify factors that contributed to firefighter deaths in an incident, as well as to provide findings and recommendations in public reports to prevent future tragedies,’’ officials at the program said in an e-mailed statement.
The agency, which conducts research and makes recommendations to prevent worker injuries, does not examine issues related to legal or regulatory requirements for fire departments, the officials added.
Acting Fire Commissioner John Hasson invited the team, which usually includes fire chiefs from across the country, to investigate, said Steve MacDonald, spokesman for the Boston Fire Department.
The Fire Department’s board of inquiry, which has 11 members, also began an investigation last week. That team, headed by Deputy Chief Michael Doherty, will spend the next several months looking at various aspects of what happened during the blaze, MacDonald said.
“They will be looking at operations, the communications, the weather; they will be looking at everything,’’ MacDonald said. He said the panel could complete its work by the fall.
In addition to interviewing firefighter witnesses, the board will listen to dispatch recordings, review photographs, and may ask the public for photographs taken before, during, or after the blaze, MacDonald said.
The board of inquiry will follow the line-of-duty death investigation protocol established to investigate those cases, MacDonald said.
Walsh and Kennedy were killed March 26 after they became trapped in the basement of 298 Beacon St. during a nine-alarm fire. Frantic calls for water to douse the fire were heard on audio recordings.
Last week, authorities disclosed the cause and origin of the blaze: It was ignited by sparks from welders working on an iron handrail at the building next door.
The workers had been working without a city permit, which usually requires a Fire Department official to inspect the work site for potential hazards and decide whether a fire detail should be present.
Investigators determined that fierce winds blew sparks from the welding job at the back of 296 Beacon St. onto the clapboards at the rear of 298 Beacon St. The fire smoldered, traveled up inside the walls, and fed on the dry wood, authorities said.
The national team investigated the 2007 blaze in which firefighters Paul J. Cahill and Warren J. Payne perished while responding to a fire at Tai Ho Mandarin and Cantonese Restaurant on Centre Street in West Roxbury.
Cahill was on the lead end of a fire hose, heading into the kitchen, and Payne, who was responsible for helping with a preliminary search for victims, was in the kitchen, when the roof in the kitchen imploded, authorities said. Payne was killed instantly in a massive fireball. Cahill probably died from either a heart attack or suffocation, they said.
The National Institute for Occupational Safety and Health also investigated the 2009 death of Lieutenant Kevin M. Kelley, who was killed when a ladder truck hurtled down a hill and crashed into a building on Huntington Avenue in Mission Hill.
The truck was carrying Kelley and three other firefighters back from a routine medical call when it went down Parker Hill Road, rumbled through the intersection at Huntington Avenue, smashed into two parked cars, and struck the building.Meghan Irons can be reached at Meghan.Irons@globe.com. Follow her on Twitter at @MeghanIrons.