A provincial fire official says a huge four-alarm fire that destroyed two restaurants in Toronto's upscale Yorkville area Christmas night has not yet been deemed suspicious.

Although Toronto fire officials had originally called the fire that took out Spuntini Ristorante & Bar and Sotto Sotto Restaurant “suspicious,” Peter Hamilton of the Office of the Ontario Fire Marshal said Saturday it is still too early to determine any cause.

“We have not ruled anything out and all things are still on the table,” he said outside the scene at 116 Avenue Road. “We have not conducted any scene investigation as of yet.”

Hamilton said a large amount of debris will need to be removed before he and other investigators can enter the building. Once they’re in, the investigation could take several days, he said.

“Inside the building, due to the construction techniques used at that period of time, the entire building has slid down inside,” he explained.

Earlier on Saturday afternoon, Toronto fire platoon chief Colin Reid said a building collapse is still possible.

Emergency crews were called to restaurants just before 7:30 p.m. on Thursday.

At the peak of the fire, some 22 fire trucks and 90 firefighters battled the blaze. Fire officials say it caused more than $1 million in damage.

Peter Catario, co-owner of Spuntini, said on Friday that he was “traumatized by this.”

Fernando Esteves, Spuntini’s other co-owner, said on Saturday that they may or may not rebuild.

Esteves said the restaurant had been closed for two days before the fire, and that he was in Arizona when he learned about the fire through an email from his alarm company.

Marisa Rocca, owner of Sotto Sotto, issued a statement on Friday promising that she would rebuild. "We owe it to our history, our team and our loyal patrons to rebuild and we will come back stronger than ever," Rocca said in the statement.

So far, fire officials believe the fire began at 116 Avenue Road before spreading to the neighbouring building, 114 Avenue Road.

Hamilton said that 114, another building that suffered some damage, was returned to its owners on Friday.

He also said that his office was working with Heritage Toronto, which looks after historically important buildings.

The fire was initially being treated as suspicious because the building had been unoccupied for a few days and because of the extent of the damage, Toronto Fire Services had said.

The two restaurants were closed at the time, and officials said the tenant who lived in the apartment above the restaurant was away visiting family, according the Toronto fire.

Both restaurants have been landmarks in the Yorkville community for over two decades, popular with celebrities during the Toronto International Film Festival.

A section of Avenue Road that was closed after the fire was expected to stay shut on Saturday.

Fire fighters remained at the scene overnight Friday in case of a building collapse.

According to fire officials, the heat from the fire was so extreme that at times firefighters were forced to back away.

Flames were seen coming out from the building, and heavy smoke was visible on the street.

"We looked over at the restaurant and we noticed a lot of smoke coming out," a witness told CTV News. "At first I thought it was someone doing laundry or something, but then we realized it was billowing. We called 911 right after that."

One firefighter sustained minor burns, but was treated on the scene and remained on duty.