A seven-alarm fire broke out around midnight Sunday at a building in Paterson that displaced at least 17 people, authorities say. Fire officials say the main portion of the flames were in the rear of the building at 195 Broadway.

Throughout the morning and early afternoon, firefighters continued to put out hot spots.

The mixed-used building at the intersection of Broadway and Straight Street is a complete loss, including three businesses on the ground floor and 15 small apartments on the upper floor.

Crews were at the scene demolishing the building Sunday evening. They said they would continue to search for a man who is unaccounted for.

Mayor Andre Sayegh told News 12 that it was not safe for crews to search the building without beginning to tear it down.

“Our focus right now is to find that gentleman who's unaccounted for. What I do know is he's a senior citizen. So time is of the essence. We want to make sure that we're able to locate him because, of all the people have been displaced, he's the only one that we don't know anything about right now as far as where he might be,” Sayegh said.

Sayegh also said he and law enforcement are thoroughly working to locate the person.

“I’ve been in constant communication with our fire chief, we’re coordinating with the police department,” he said. “We’ve called the landlord, I know they’ve reached out to family members as well.”

Contractors said the brick building was structurally weak. Displaced residents said it didn’t have sprinklers installed.

Crews will continue to search throughout the night. They said Sunday night that it would be some time before the street returns to normal.

“We still have a significant cleanup,” said Bill Vecharello, of Vecharello Contracting, LLC. “We have to notify the state. [Monday,] the building will be down. It will be fenced-in so it'll be safe for the people to walk through the neighborhood. But, I would say at least another week.”

Members of the fire department were on-scene for more than 20 hours - continuing to douse hot spots into the night.

“If it were not for their remarkable response, this would have been far worse,” Sayegh said.

Officials believe the fire started in the rear of the building near apartments. Viewer video shared with News 12 showed flames developing in the back of the building.

"There's apartments in the back of the building that go below grade so when you're going on the first floor, there's actually a basement with apartments in the rear. So, the fire had the chance to spread throughout the basement area first floor and second floors," said Deputy Chief Arthur Woods.

Upon arrival, firefighters found heavy smoke and flames coming out of the building and were trying to get people out. They described the scene as chaotic.

"People were coming out, they were disorientated. Firefighters escorted them outside. The main building is a complete loss. We have no reported injuries. A couple of victims have smoke inhalation and some heat-related on the outside. No major injuries," Woods said.

The Red Cross told News 12 they have assisted 11 people from six families.

The Kinchen family told News 12 they were getting ready to go sleep just after midnight when the smell of smoke filled their home.

"My wife was like 'Babe, I smell smoke,'" said Torrie Kinchen. "...I went to the door, opened the door and [saw] all the smoke from... the hallway. So I just panicked and got them together and just left."

When he got outside, he could not believe the building he spent the last 13 years living in was up in flames.

Sayegh said the city will help the impacted businesses.

"We'll do everything we can to provide the appropriate assistance," he stressed.

A six-story apartment next door had its utilities turned off and all residents were evacuated as a safety precaution. The Red Cross said those people would be able to go back to their apartments at some point Sunday. The fire chief said although the fire did not spread to that building, it does have smoke and water damage.

A cause of the fire was still unknown as of Sunday night.