The fire broke out around 1:30 a.m. and took firefighters about two hours to contain.
Retired police Detective Sergeant Wally Zeins said fire investigators believe the fire cause was electrical in nature and may have been caused by something plugged into an outlet in the building.
Students in nearby dorms woke up to the sound of sirens and to the sight of their beloved school building burning.
An untold number of student art projects inside were damaged or destroyed. The building is normally open to students around the clock.
The fire started, investigators say, on the sixth floor.
Sources tell PIX11 News there are no sprinkler systems on the six floor where the fire started. There was no burglary, but apparently sources say a burglar alarm wire caught fire and tripped the alarm notifying security who then notified the fire department.
There were no major injuries, but two firefighters were taken to the hospital for smoke inhalation.
Fire investigators plan to interview students. The Pratt Institute said that classes in the Main Building and nearby South Hall were canceled Friday, and they will be on Saturday as well.