Toronto Police say a downtown intersection will remain closed as they deal with the aftermath of a brick wall that collapsed onto a sidewalk.

"We are unable to access the area at this time because it's still unstable. Bricks are still falling to the street," Supt. John Tuanoyue told reporters at a 2 p.m. Friday news briefing.

The affected building, which sits at the corner of Yonge and Gould Streets, has been evacuated.

At 6 p.m., inspectors could be seen examining the building from a cherry-picker.

The collapsed wall was directly adjacent to the popular Salad King Thai restaurant on the south side of Gould Street, and above the relatively new Tatami sushi restaurant.

"It looks like the whole front of the building, the concrete part, has fallen onto the street," Natalie Blaise, a Ryerson University journalism student, told CTV News. "You can see the insulation peeking through."

The area of building affected by the collapse is about 10 metres in length by three metres in height.

Police have closed the area to traffic: Yonge is closed between Gerrard and Dundas Streets, and Gould is closed between Yonge and Victoria Streets.

Officials are concerned about the Yonge Street side of the building, fearing it could be just as unstable as the Gould Street side.

Witnesses heard a tremendous amount of noise and then saw the dust rise. People inside the restaurant told reporters the dust came inside, forcing them to cover their mouths.

Another person inside Tatami said the dust came at him like an ash cloud from a volcano, while another person observed he had walked along that sidewalk about five minutes before the bricks showered down.

Police have used a cadaver dog and a thermal imaging camera to determine whether anyone was caught under the rubble, but no workers were seen actively digging in the wreckage.

Later in the afternoon, officers said they were relatively certain no humans were trapped under the rubble.

No reports of missing persons have been filed.

Toronto EMS did not transport anyone to hospital. Const. Wendy Drummond said "miraculously, nobody's reported any injuries. Nobody's been reported hurt by any falling debris."

Eby said inspectors will have to be certain the structure, once known as the Edison Hotel, is safe before anyone can go inside. But as of 6 p.m., there was still no word on the cause of the collapse.

With a report from CTV Toronto's Chris Eby