TORONTO -- Fire crews continue to battle a blaze that broke out at a restaurant in Mississauga, Ont. Sunday evening.

Firefighters were called to a Paramount Fine Foods restaurant at the Erin Mills Town Centre in the area of Eglinton Avenue West and Erin Mills Parkway just after 6 p.m.

Viewer video shows visible flames on the roof of the restaurant as heavy smoke billows out.

Mississauga Fire

When crews arrived, they entered the structure and began an offensive attack. But due to unfavourable conditions at the time, they were forced to retreat.

"It was high heat conditions, low visibility, high smoke. It became untenable inside. And the incident commanders pulled the crews outside," Mississauga Fire Chief Deryn Rizzi told CP24.

"So, we moved to a defensive attack. You'll see multiple aerial trucks behind me. We have four ladders up plus a deck gun going right now."

Rizzi said shortly after crews were pulled out of the restaurant, the roof collapsed.

The firefighters were able to do a primary search, she said, and an all-clear was called.

There was an unknown number of workers inside the restaurant at the time, Rizzi said, adding that they had 'little awareness' of the situation as the fire was above the drop ceiling and in the roof.

An individual passing by the restaurant who saw the roof on fire ran inside and alerted staff, she said.

Mississauga Fire

The cause and origin of the blaze have not been determined.

Rizzi said a fire investigator is at the scene, and the Office of the Fire Marshal has been notified as the damage caused by the blaze is estimated to be over $500,000.

"Obviously, they're going to investigate the origin and cause, so I won't be speaking any further about what it may or may not have been caused by," she said.

Rizzi noted that crews will remain at the scene for several more hours.

"Normally, the next phase would be our overhaul phase, but because of structural instability, we may not be able to get our firefighters inside to check for hotspots," Rizzi said.

Mohamad Fakih, the chief executive officer of Paramount Fine Foods, came to the scene to check up on the employees. He said he is thankful that none of the staff and customers were hurt.

"For the community, we only need your prayers and your support. As I always say, I believe that light will come. This year has been a hard thing for everyone, and for us to get this by the end of the pandemic, hoping this is the end of the pandemic, it's very tough," Fakih said.

"I just need the support and the prayers of the community. We don't need anything from the community. We're always here to serve this community, and we will continue doing that."