The mayor of the American megalopolis, Eric Adams, did not immediately explain why the record was lower.
Meanwhile, medics were still trying Monday to rescue victims who were seriously injured in the disaster.
Many lost consciousness or found themselves trapped in their homes during the disaster that broke out in the Bronx.
Dozens of people have been hospitalized.
Mayor Adams said Monday that several victims are in critical condition, and he admitted to CNN that the death toll could rise.
We pray to God that they survive, did he declare.
It was the deadliest fire to break out in New York City in more than 30 years.
Investigators have determined that flames erupted in the 19-story building after a small space heater malfunctioned that was plugged in on a cold morning.
The flames caused only modest damage, but smoke filled the stairs. This was the only way to escape a building too high for emergency exits.
The smoke was so dense that some residents were unable to escape, Fire Marshal Daniel Nigro said. Others were inconvenienced trying to get out.
Firefighters found victims on all floors, including several who were in cardiac or respiratory arrest, according to Nigro.
Unconscious children have been seen receiving oxygen after being taken from the building. Some who managed to get out were covered in soot.
Firefighters continued to rescue victims even after they themselves had exhausted their oxygen reserves, Mayor Adams said.
Their oxygen tanks were empty and they still entered the smoke, he said.
A faulty door to blame?
Commissioner Nigro said an investigation has been launched to determine how the fire spread and whether something could have been done to prevent or contain it.
Mr Adams revealed that the smoke may have spread because a door that should have closed automatically had been left open.
There might have been a maintenance issue with this door. And that will be part of the investigation, he told ABC Network.
New York City apartment buildings are to be equipped with sprinkler systems and interior doors that close automatically to prevent smoke from spreading and to deprive flames of oxygen, but these rules do not apply to homes. thousands of older buildings.
The building is equipped with smoke detectors, but several residents said they ignored them early on since false alarms were common.
It is the deadliest fire to occur in New York since 1990, when 87 people were killed in an arson attack at the Happy Land club, also in the Bronx.
The neighborhood was also the scene of fires that killed 13 people in 2017 and 9 people in 2007.