Lithium-Ion Battery Failure Identified as Cause of Fire That Killed Boston Firefighter Bobby Kilduff Jr.

Lithium-Ion Batteries Caused Fire That Killed Firefighter Robert Kilduff Jr.

“These batteries power so much of our lives, but also carry many risks,” Boston Mayor Michelle Wu said during a press conference on Wednesday.

Months after a tragic blaze claimed the life of a veteran Boston firefighter, city leaders have officially identified the origin. The May 23 fire at 18 Treadway Road in the Dorchester neighborhood was triggered by thermal runaway involving multiple lithium-ion batteries stored inside plastic toolboxes on a third-floor enclosed porch, Boston Fire Commissioner Rodney Marshall announced. The findings point directly to the rapid overheating phenomenon where a battery produces more heat than it can dissipate. The batteries experienced “thermal runaway,” Marshall said.

Robert “Bobby” Kilduff Jr., a 24-year veteran of the Boston Fire Department, a U.S. Marine Corps veteran, and a third-generation firefighter, suffered severe injuries after falling from the third-floor porch during the incident. He was transported to Boston Medical Center, where he later died. He left behind an adult daughter and son, and his funeral was held on Monday. “We recognize that this incident has had a profound impact on this department, the Kilduff family, and the entire Boston community,” Marshall said.

Official Updates From City Hall and Fire Headquarters

Mayor Wu and Commissioner Marshall delivered the update at Boston Fire Department headquarters in Roxbury, emphasizing the growing dangers associated with common household power sources. “Today, we want to emphasize the importance of lithium-ion battery safety,” Marshall said.

While the immediate physical cause is now established, city officials stressed that the overarching inquiry remains active. Marshall noted that multiple reviews are still underway to examine every circumstance surrounding the line-of-duty death, urging patience as those administrative and safety checks proceed without speculation. “These investigations will examine all of the circumstances surrounding this tragedy. “The broader investigation into the line of duty death of Firefighter Kilduff remains ongoing.”

Users must ensure that batteries are certified by nationally recognized testing organizations like Underwriters Laboratories, charged exclusively with original equipment on hard surfaces, kept at room temperature, and utilized strictly for their intended designs. Marshall added that batteries should be kept out of direct sunlight and that devices like hoverboards and e-bikes should not be charged near exit points.

Investigators Probe Tragedy as Battery Accidents Rise

The National Institute for Occupational Safety and Health, alongside the Boston Fire Department’s Board of Inquiry, is conducting separate investigations into the tragedy. District Fire Chief Keith Kelley warned that accidents involving these power sources will likely increase as more units enter residential households. “As more and more batteries enter people’s households, we’re going to have more accidents,” Kelley said.

Municipal leaders continue to work on initiatives to honor Kilduff’s legacy and support his grieving family. Further updates on the federal and departmental safety findings will be released to the public as the review processes advance. “He made the ultimate sacrifice in service to our city and we’re continuing to work on several efforts to honor his legacy and support his family,” Wu said.