Officials said smoke from a manhole was followed by flames from a transformer vault.
EAST WILLIAMSBURG, N.Y. — A fire that erupted from underground utility equipment in Brooklyn on Wednesday sent carbon monoxide into a nearby residential building, forced more than 200 people to evacuate and left at least two people hospitalized, officials said.
The emergency began as a call about dangerous air inside the building, but it quickly grew into a street-level blaze that damaged vehicles and required hours of careful work underground. Fire officials said crews had to cut off gas supply lines and manage lingering fumes while also keeping flames from spreading to nearby structures. Investigators were examining what caused the underground fire and whether winter conditions contributed to damage in utility systems beneath the street.
Crews responded around 3:30 a.m. after reports of smoke coming from a manhole near 101 Humboldt St., officials said. Firefighters checking the building found elevated carbon monoxide levels, and residents were told to leave as a precaution that soon became urgent. Officials said the incident escalated into a gas leak concern, adding another layer of risk to an already complicated response. Firefighters moved hoses into position and began cooling nearby building fronts, a standard tactic meant to prevent heat from cracking windows or igniting material along the sidewalk line.
Over 200 residents were evacuated from the seven-story building, officials said, and at least two people were taken to the hospital by medics. Authorities did not immediately release their names or conditions. Outside, flames intensified as the underground fire expanded, and by about 5:15 a.m. smoke gave way to visible fire that scorched two parked cars near the curb. Officials said the flames were shooting out of a transformer vault, an underground chamber that holds electrical components and can connect to manholes and other access points along the block.
The operation stretched for much of the morning because underground fires can continue to burn even after surface flames appear to fade. Officials said firefighters turned off valves that feed an underground gas line, a step meant to reduce the chance that escaping fuel could worsen the incident. The next challenge was the residual gas and heat trapped below ground, which can seep into buildings or flare if disturbed. Crews kept water flowing, monitored conditions and worked to gain control while limiting disruptions to the surrounding area.
Authorities said they were investigating what sparked the fire and were also considering weather-related causes that can affect underground utilities in winter. FDNY Battalion Chief Barry Leguernic said salt on roads and sidewalks can contribute to wear on utility systems. “During the winter months with the salt on the ground, we do get the electric utilities get affected,” Leguernic said, adding that it was too early to say exactly what failed or how the situation escalated after the initial problem. Officials did not immediately say whether electrical service was interrupted or whether any underground equipment would need replacement.
For many residents, the most frightening part was how quickly an air-quality concern turned into a visible street fire. Ruben Burgos said he traveled about two hours to check on his 80-year-old father after hearing about the evacuation. Burgos said he expected building alarms to provide early warning, but he questioned whether that happened. “One confusing thing to me was everybody has carbon monoxide tests, not one went off in the building,” Burgos said. Another resident said the incident raised new worries about safety in the building, calling carbon monoxide “a silent killer” and asking whether protections would be enough if the problem returned.
The Red Cross assisted evacuated residents, officials said, helping people who needed support while crews worked to clear the building and stabilize the street. Firefighters continued to hose down nearby structures and keep the area secured as investigators began documenting the scene, including the damaged cars and the underground access points tied to the fire. Officials did not say how long residents were kept out or whether any apartments sustained smoke infiltration, but they said the focus remained on ensuring safe air levels before normal activity resumed.
By later Wednesday, officials said firefighters had gained the upper hand after about seven hours, and the cause remained under investigation. Authorities said updates would follow as investigators review the underground equipment and the sequence of events that led to the evacuation and injuries.
Author note: Last updated February 19, 2026.