The fire broke out in the basement of the home on Grove Street, near Route 440, just before 3:30 a.m.
Heavy flames tore through both stories of the home and then shot through the roof.
One firefighter got trapped on the second floor and had to be rescued by other firefighters. He was taken by helicopter to St. Barnabas Medical Center with unknown injuries. Two other firefighters suffered minor injuries.
Firefighters battled the blaze for hours. It appeared they were getting control of the fire before more flames shot out the roof.
The cause of the fire is under investigation.
About 16 residents of the building on fire and an adjacent house were forced out of their homes.