FDNY sifts through Trump Tower apartment after fatal blaze

FDNY fire marshals investigating the cause of the deadly fire inside Trump Tower were sifting through evidence and analyzing what was left of the charred apartment Sunday, officials said.

They were focused on the 50th-floor apartment that belonged to Todd Brassner, a 67-year-old art dealer who died in the blaze Saturday night, hoping to identify what sparked the fatal inferno.

Brassner's apartment in the Fifth Ave. high-rise became completely engulfed after the blaze was sparked about 5:30 p.m., with flames soon blasting out the windows. The four-alarm blaze was brought under control at 7:40 p.m.

See photos from the Trump Tower fire:

Fire marshals were working to piece together where in his apartment the fire originated and how the flames were able to spread so rapidly through the large unit. The lack of sprinklers on the tower's upper floors, where Brassner lived, was identified as a contributing factor.

"The entire apartment was on fire," said FDNY Commissioner Daniel Nigro at a press conference at the scene Saturday. "The fire was a difficult fire. The apartment was quite large and 50 stories up."