However, there is no word yet on what sparked the blaze.
It will be several more days before the investigation is complete.
The fire erupted around 3:30 p.m. Wednesday in the unit block of Taylor Court at Building 8 of the Avalon Princeton Junction Apartments.
Twenty-two people from seven families are now without homes.
The view from Chopper 6 showed flames shooting through the roof of the three-story apartment building.
With daylight Thursday morning, the severe damage the fire caused could be seen. The roof is gone from the building and the siding is melted away.
Roughly 200 firefighters battled the blaze for four hours. A fourth alarm was struck just before 5 p.m. before it was brought under control an hour later.
No residents were injured in the fire. Four firefighters suffered minor injuries.