Investigators are treating an east-end fire that blackened the Toronto skyline on Thursday afternoon as "suspicious."
Officials said they have not been able to go inside the auto wrecking yard, near Victoria Park and Danforth Avenue, because the area is still too hot and unstable.
But witnesses have reported seeing people fleeing the scene when the fire began at around 2 p.m.
The blaze quickly spread, forcing the evacuation of nearby residences.
Some GO Transit routes were also suspended during the fire. Service resumed Thursday evening, but the aftermath caused delays during the Friday morning commute.
An official with the Fire Marshal's office said investigators will need the public's help to determine what caused the five-alarm blaze.
"We're going to rely heavily on statements from witnesses," Mariano Perino said.
"We'll have to determine if (they) corroborate what we can find at the scene."
During the fire, health authorities were concerned about the massive amount of smoke.
Friday morning, the fire had dissipated -- but some residents think water seeping from the scene into the neighbourhood could be toxic.
One woman said the wrecking yard, which has been in business for 70 years, has overstayed its welcome in the area.
"It is becoming more residential, so they really don't need to be there," Cindy Marshall said.
With a report from CTV's Roger Petersen
