Twenty-two people from seven families are now without homes.
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.
The flames broke out at about 3:30 p.m. in the unit block of Taylor Court at Building 8 of the Avalon Princeton Junction Apartments.
Views from Chopper 6 showed flames shooting through the roof of the three-story apartment building.
"They had heavy fire on arrival from the second and third floor and it quickly extended from there," said Lt. Mike McMahon with the West Windsor Township Police Department.
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.
"The flames were coming out of the right side of the building, and after about 10-15 minutes, they spread across the roof. It was so fast, it was so scary, and I started crying because I felt for all the people," said resident Christina Wilson.
The fire, contained to Building 8, destroyed 24 apartments on the property, but no one living in them was injured.
"There is a fire separation in the building construction. The way the fire broke, it appears it got on both sides of that," said Lt. McMahon.
Four firefighters suffered minor injuries.
The displaced residents are being assisted by property management and the Red Cross.
The cause of the fire remains under investigation.