The fire was called in just after 9:15 a.m. and officials say it was under control in about 30 minutes.
About 75 firefighters responded to the scene.
Six firefighters suffered minor injuries and were transported to Jersey City Medical Center.
The fire spread from one home to two others through the connected cocklofts.
The Red Cross is assisting those who were displaced by the blaze.
The cause of the fire remains under investigation.