Updated

A two-alarm fire at a residential building at 850 Intervale Avenue in the Bronx borough of New York City on Tuesday has left eight people injured and at least one dead, according to local authorities. Several days after the incident, on Saturday, video circulated on social media showing the moment of the explosion. 

"When you see the body cam video, you're going to see the quick response of the officers going into a burning building next door from the explosion — not realizing if [there] would have been an additional explosion — but they went inside and carried out a woman who was trapped inside," Mayor Eric Adams said Tuesday. "And we're hearing countless stories from those who are in the hospital who are the homeowners in this area."

PHOTOS: BRONX APARTMENT BUILDING FIRE KILLS MULTIPLE PEOPLE, INCLUDING CHILDREN, FIREFIGHTERS AMONG INJURED

At least three civilians and five police officers sustained injuries. Two of the individuals injured are in critical condition, Mayor Eric Adams said during a Tuesday afternoon press conference.

One 77-year-old female has been pronounced dead, according to the New York Police Department (NYPD) and New York City Fire Department (FDNY).

John Hodgens, FDNY department chief, said the department responded to the fire within four minutes of receiving a call on Tuesday morning.

Officials found two sisters, who were inside the building when it exploded, "on the ground outside" after the blast and transported them to a nearby hospital. One of the sisters succumbed to her injuries and was pronounced dead at the hospital, Hodgens said.

Jan. 18 Bronx fire. (WNYW)

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New York City Councilman Rafael Salamanca attributed the "massive fire" to a "gas explosion" at the building on Intervale Avenue in the 17th District, which he represents. 

"Just received word that [energy company Con Edison] will be shutting down the gas in the immediate area along Fox Street between Intervale Ave & Tiffany Street," Salamanca said in a Tuesday tweet. "With temperatures dropping, we will continue to monitor to ensure a restoration of gas once it is safe to do so."

John Hodgens, FDNY department chief (Fox 5 New York)

John Hodgens, FDNY department chief (FOX 5 New York)

Alfonso Quiroz, a spokesperson at the New York-based energy company, confirmed to Fox News Digital that it has turned gas off on the block and is working with the FDNY "to investigate" the root cause of the apparent explosion.

Quiroz added that there is a "large debris field that the fire department will need to" sort through in order to determine the cause.

The fire, as well as response efforts from the NYPD and FDNY, were ongoing as of 1 p.m. Tuesday, and the building on Intervale Avenue had partially collapsed. The fire began just before 11 a.m., as FOX 5 New York first reported.

Jan. 18 Bronx fire. (WNYW)

Residents of nearby buildings were evacuated to a church in the neighborhood, according to FOX 5.

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The explosion comes about one week after 17 people, including eight children, died in a Jan. 10 fire that destroyed a Bronx high-rise apartment building.

FDNY, NYPD and other local officials continue to investigate the fire.