Mr Brassner was found "unconscious and unresponsive" and was taken to Roosevelt Hospital, where he died.
His brother, Howard Brassner, owns a gallery named Art Link International in Lake Worth, Florida, The Palm Beach Post reports, citing state records.
He bought the spacious unit back in 1996 and had reportedly fallen on harder financial times, recently declaring bankruptcy.
US President Donald Trump has a home and an office in the building, but is now in Washington. The four-alarm blaze at the 58-story building on Fifth Avenue at 57th Street in Midtown was quickly quelled, although not before debris from the blaze fell to the streets below.
As the New York Dailiy News points out, Trump has previously fought legislation that would require buildings in New York City to require sprinklers. "Members pushed in heroically, they were knocking down the fire and found one occupant of the apartment who is in critical condition", the fire service quoted him as saying.
Mr. Trump's family has an apartment on the top floors of the 58-story building, but he has spent little time in NY since taking office.
The upper-level residential floors are not equipped with fire sprinklers, according to Nigro.
Some residents said they didn't get a notification to evacuate the building.
At the time, Trump responded by imploring at least six city council members to lobby against the rules and even donated to the city speaker. It said the four firefighters had "non-life threatening" injuries and that the blaze had been brought "under control". Eric Trump, the president's second-oldest son, tweeted that the fire was in a residential apartment at the tower.
'Very confined (well built building). "Firemen (and women) did a great job", the president wrote on Twitter at 6:42 p.m.
The blaze broke out roughly three months after two people were injured in a fire at the President's flagship property. "NY instead has required that new construction be fire resistant".
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