The fire was believed to have started in an apartment above a pizzeria on Broadway in Bayonne just before 10 p.m. Monday.
It then spread to two floors of a three-story brick building next door.
There were no reports of any injuries, but the buildings had to be evacuated.
Now, business owners are hoping to salvage anything from the gutted building.
Two residents of the original fire building were hurt, while six people - four adults and two children - were left homeless.
The cause of the fire is under investigation.