A public housing tower partially collapsed in the South Bronx on Wednesday morning due to an explosion, forcing residents to evacuate, New York City officials said.

No injuries or fatalities were reported as the fire department and other agencies responded to the scene and began remediation and relocation efforts.

The building at Alexander Avenue and East 137th Street is part of NYCHA's Mitchel Houses, officials confirmed. They warned people to avoid the area as first responders continued their work.

The FDNY said a ventilator shaft collapsed from an explosion and firefighters were investigating a potential gas leak. City emergency management officials said utility company Con Edison has shut off the gas to the building and a community center at Alexander Avenue has been set up as a temporary shelter.

FDNY firefighters respond to the scene of the collapse.

NYPD officials said no housing units appeared to be damaged by the collapse. Police responded to a 911 call for the address around 8:10 a.m., including officers from the department’s aviation and emergency service units.

The city's buildings department said it was also responding to the incident. Authorities said residents who live on two of the tower’s apartment lines were evacuated, and others could return once safety inspections are completed. Gas and hot water to the Mitchel complex was suspended after the incident, according to officials and tenants.

A spokesperson for NYCHA said early reports indicate there was an explosion in a chimney, but an incinerator was not involved. She said investigators were working to determine the cause of the incident and any damage beyond damage to the chimney.

Mayor Eric Adams said a “full assessment” of the incident is ongoing.

“We are extremely fortunate at this time we have no loss of life or injuries,” he said at a press conference following the incident. A mound of debris and fallen bricks could be seen near the building.

Eusebia Sosa, 76, who has lived in the building for 44 years, was being comforted outside by her granddaughter following the collapse. Sosa said she was concerned about her two dogs, which were frightened by the explosion and ran under her bed.

Her granddaughter, Aishah Evans, said NYCHA rarely makes repairs at the building.

"They never fix anything. Never," Evans said, noting they visited the property management Friday to request Sosa’s floors be fixed.

A playground is located near where the building partially collapsed.

Isabel Sanchez, who lives in an adjacent building, said she witnessed the collapse after hearing what sounded like cement cracking.

“I was scared for a moment,” she said, adding that she saw the bottom of the affected section of facade slide off and the rest come cascading down.

Emergency Management Commissioner Zach Iscol said crews were transitioning to the “recovery” phase of their response late Wednesday morning and aiming to restore heat, hot water and cooking gas to the complex. He said tenants could access resources at the Mitchel Community Center, including relocation services for those who need alternative housing.

City Councilmember Diana Ayala, who represents the area and was on the scene early Wednesday, said structural engineers will visit each apartment to ensure they are safe. The problems that appeared to lead to the partial collapse are “a symptom of a bigger issue in the lack of investment in public housing,” she said.

Bronx Borough President Vanessa Gibson said the city avoided “a major disaster” as no one was hurt in the incident.

“Many people had already left for their day, going to work and other places, children were in school,” she said. “We will make sure residents are provided with food and other necessities as we ensure the inspections are done in an efficient manner.”

The incident recalled another in the Bronx in December 2023, when a section of a seven-story apartment building in Morris Heights crumbled to the ground after construction workers removed load-bearing bricks from a corner of the property. No one was injured in that collapse, but at least six families were displaced for months after their apartments were destroyed.

This story has been updated with additional information.