The 4-alarm fire started just after 9 p.m. Wednesday at 24 Broadway and quickly spread to three neighboring buildings, destroying two of them.
Firefighters scrambled to prevent it from spreading further.
A portion of the roof in the initial fire building collapsed, and a collapse zone was et up in case more of the building came down.
PSE&G was at the scene to shut off a gas line that was feeding the fire. Fire departments from several surrounding towns also responded to the scene.
The fire was declared under control early Thursday morning, but fire officials were still trying to control hot spots late into the afternoon.
One particularly stubborn hot spot is between an air shaft, where the original fire began, and the building to the right.
Two of the buildings appeared to be three-story, mixed-use buildings with stores on the first floor and apartments above them. The third building that caught fire is a one-story commercial building. Details on the fourth building were not known.
The fire caused the evacuation and displacement of 15 families and approximately 100 residents. The city has established the Senior Center as a temporary shelter for residents and families impacted by the fire.
No injuries were reported.
The cause is under investigation.
If you or anyone you know want to help the families affected by making donations, please contact the Mayor's Office in the City of Passaic at 973-365-5512.