A fully-involved fire inside an eight floor unit at a downtown high-rise has been put out and an investigation will now begin to determine its cause.

Firefighters were first dispatched to the building on Dundas Street near Church Street at around 4 a.m. for an alarm call.

When they arrived they were directed to the third floor where police had responded to a call for a possible stabbing. Police tell CP24 that the victim in that incident sustained non-life threatening injuries.

Meanwhile, subsequent firefighters arriving on scene spotted visible smoke coming from the eight floor and began a fire investigation.

“It took some time because the alarm panel only showed the third floor. So crews outside were directing the interior crews to roughly where the smoke was emanating from and then crews started investigating,” Platoon Chief Kevin Aucoin told CP24 at the scene. “We eventually got to the eighth floor and found the smoke and then crews found the apartment of origin.”

Aucoin said that the fire was “very intense” but was knocked down relatively quickly by firefighters.

A man who lives in the unit where the fire occurred told CP24 that he had someone staying with him and had left the apartment to take care of some errands.

“I am still in shock and trying to process what happened,” he said.

Residents in the rest of the building were told to shelter-in-place as crews battled the fire.

At one point, 12 fire trucks were on scene.