Battery Safety: Lithium-Ion Toolboxes Caused Dorchester Fire That Killed Boston Firefighter
City officials announced the specific origin of the blaze that led to the death of a veteran firefighter in May, citing thermal runaway in stored power sources.
By Natalia Costa ·
Lithium-ion batteries stored in plastic toolboxes caused the three-alarm fire that killed Boston Fire Department veteran Robert Kilduff Jr., city officials announced on Wednesday, November 4.
Boston Fire Commissioner Rodney Marshall held a news conference at the department headquarters to reveal the findings. He stated that the Fire Investigation Unit completed its review of the scene at 18 Treadway Road in Dorchester. The investigation determined that the fire originated in the rear portion of the building, specifically on the third-floor enclosed porch.
Marshall explained that the cause was thermal runaway involving multiple lithium-ion batteries. The batteries were kept inside plastic toolboxes. Kilduff, a 24-year veteran and member of Rescue 2, died after falling from the third-floor porch during the incident.
Firefighters arrived at the Dorchester home at 8:15 p.m. on Tuesday, May 23. About 30 minutes after their arrival, a mayday was declared. Kilduff fell from the third-floor porch and was transported to Boston Medical Center, where doctors pronounced him dead. He was a third-generation firefighter and a U.S. Marine Corps veteran.
A portrait of Kilduff was added to the display of fallen firefighters just below the ceiling of the headquarters this summer. Marshall stood near the photo during the announcement. He clarified that while the origin and cause investigation is finished, the line-of-duty death investigation is still open.
The National Institute for Occupational Safety and Health and the Boston Fire Department’s Board of Inquiry are currently examining the circumstances. Marshall said the department will wait for those processes to finish before drawing conclusions. He emphasized that findings will be shared when the respective investigations conclude.
Fire Chief Keith Kelly of the Special Operations Command joined Marshall to discuss safety measures. Kelly noted that lithium-ion batteries are common in phones, vacuums, power tools, scooters, and drones. He advised residents to store these batteries at room temperature on hard, stable surfaces. He also recommended routine checks for swelling, leaks, or corrosion.
Kelly warned against charging batteries that appear compromised. He suggested purchasing batteries certified by testing companies like Underwriters Laboratories. He advised using the original charging cable and avoiding cheap knockoff batteries found online, which he identified as a common cause of thermal runaway.
Kelly, who was in Kilduff’s academy class, became emotional near the end of the conference. He stated the goal is to ensure proper storage and inspection rather than to scare the public. Mayor Michelle Wu joined the officials to comment on the findings.
Wu described the batteries as essential to daily life but noted they carry serious risks. She said the city owes it to residents to educate them on prevention. Wu honored Kilduff’s service and sacrifice, stating the city is working to honor his legacy and support his family while understanding exactly what happened at the fire.
