PASSAIC, N.J. (CBSNewYork) — At least six businesses were destroyed after a massive fire in Passaic, New Jersey.

The six-alarm fire started around 10 p.m. Monday on Lexington Avenue. The fast-moving flames and thick smoke could be seen shooting out of the strip of businesses.

The fire chief said it started in the kitchen of the El Chevere restaurant. The cause is not clear, but he says some of the appliances severed the gas lines which contributed to the spread, CBS2’s Jenna DeAngelis reported.

Most of the businesses were closed at the time and firefighters were able to get everyone out of the others.

“It’s sad but at least were alive because it could be worse,” said Heidi Tito, owner of Tito’s Travel Agency.

Twelve firefighters were taken care of on the scene for heat exhaustion. Not only were they fighting the fire, but also the humidity.

“Which causes the fire to back down and smoke, zero visibility,” said Passaic Fire Chief Patrick Trentacost. “At one time, we cleared the civilians probably to the next block because visibility was zero.”

Tuesday morning, crews were still hosing down the building, putting out hot spots and keeping streets blocked off and people away from the scene.

“I tired to go in this morning and they said you can’t go in because of hot spots and smoke,” said Brian Amaya, who works at a furniture store.

Meanwhile, business owners were taking in what’s left of their livelihood.

“Inside, nothing,” said Tito. “Everything is destroyed.”

Tito’s Travel Agency has been part of the strip for more than a decade.

“This is one of the risks of the business,” she said. “It’s sad, very sad because it’s not easy to restart.”

The focus now is helping businesses rebuild. Arlene Freeman helps manage the building.

“What we tried to do is relocate them in some of the stores so they can continue their business because they need to do this to survive,” she said.

“It’s very emotional, very traumatic but what can we do? It’s part of life,” said Amaya.

An insurance company is coming out to take a look at the damage and the mayor says they’ll try to make the turnaround as fast as possible for the business owners.

The cause of the fire remains under investigation.