One of people living in the house, a 19-year-old student from Hong Kong, was rescued after being trapped in the basement while the blaze burned through the property around 1:30 a.m. on Monday.
Tommy Ho, 19, awoke to the sound of his cell phone ringing. It was a friend and neighbour calling to tell him that the house was on fire. Firefighters eventually got him out of the fire, but not after at least a half an hour.
Ho reported burns on his feet, but there were no deaths in the fire. In a release on Tuesday, York Regional Police said they were launching a criminal investigation into the matter, and are trying to find out how many people may have been living inside the home.
"It is believed that there were more than 10 individuals in the residence at the time of the fire," the release said. "Investigators have not yet spoken to all of the residents and are asking anyone who has yet to speak to police to come forward."
CBC's Amanda Margison reported that witnesses told her there may have been as many as 13 tenants renting accommodations inside the suburban home at the home on Eastpine Drive, near Kennedy Road and Denison Street.
The Ontario Fire Marshall's office is investigating the cause of the fire.