Police say the call came in at around 9:20 a.m. on Monday morning and paramedics arrived to find a boy without vital signs.
The toddler was initially reported to be two years old, but a family member told CBC News that the boy was just one and a half years old.
The entire family had been sick, including the toddler's older brother, who was taken to hospital on Monday morning because of illness.
Toronto Public Health told CBC News that the coroner's office will determine the cause of death, including asking for laboratory results to see if this boy had the flu.
While police are investigating circumstances of the young boy's death, they don’t suspect foul play.