A lethal fire that broke out in Brooklyn, New York, has been deemed suspicious by officials.

The deadly inferno started in a residential building on Tuesday around 2:15am, according to ABC 7.

The three-story building, located on Fountain Avenue, was already engulfed with flames when emergency responders arrived minutes later.

One woman was killed in the disaster, and four young children were critically injured. 

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FDNY Brooklyn

Emergency responders attempt to resuscitate a victim of the structure fire on Fountain Avenue in Brooklyn, New York.

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The woman was found inside the apartment and declared dead on the scene by responders.

Three girls, ages 10, 14 and 17, and one 9-year-old boy were transported to Brookdale Hospital for treatment. Their current condition is unknown.

FDNY Fountain Avenue

Firefighters walk through the scene of the Brooklyn-area structure fire.

One adult man was also rescued from the flames and transported to the hospital in stable condition. It is believed that the rescued victims are related.

"Anytime you see, you know, a whole family like this together, this time of the night, I mean, with a fire ... the emotions outside. It's very emotional." said Assistant FDNY Chief Chuck Downey.

Approximately 60 firefighters responded to the blaze, and one received minor injuries during the rescue, according to reports.

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Accelerant was found at the scene of the fire, and officials have launched an arson investigation, according to a report from PIX 11 News.

FDNY ambulance fire

Firefighters and medical personnel prepare to transport victims caught in the Fountain Avenue structure fire.

Authorities are examining the area near the doorway to the unit, where the accelerant was found, for further evidence.

A crime scene tent was set up near the site of the disaster early Tuesday, according to NBC 4.

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The investigation is ongoing, and fire officials have not yet declared a cause of the blaze.