The blaze sent 32 people to hospitals with life-threatening conditions, FDNY Commissioner Daniel Nigro said earlier Sunday. A total of 63 people were injured.
It remains unclear what started the fire, but it is not believed to be suspicious, Nigro said.
“This is a horrific, horrific, painful moment for the city of New York, and the impact of this fire is going to really bring a level of just pain and despair in our city,” Adams said.
About 200 members of the New York City Fire Department were on scene of the fire at a 19-story apartment building at 333 East 181st Street. The fire began a little before 11 a.m. in a duplex apartment on the 2nd and 3rd floors of the building and has been “knocked down,” the FDNY said.
The door to the apartment was left open, and smoke then spread to every floor of the building, he said.
Firefighters were met by “very heavy smoke, very heavy fire” in the hallways.
Victims were found in stairways on every floor of the building, many in cardiac arrest, in what Nigro said could be an unprecedented loss of life. The injuries were predominantly from smoke inhalation, he said.
The FDNY posted several images of the scene showing ladders extending into apartment windows as well as a number of broken windows.
“This is going to be one of the worst fires that we have witnessed during modern times here in the city of New York,” Adams said.
“I am horrified by the devastating fire in the Bronx today,” New York Gov. Kathy Hochul said on Twitter. “My heart is with the loved ones of all those we’ve tragically lost, all of those impacted and with our heroic FDNY firefighters. The entire State of New York stands with New York City.”