Heavy smoke was reported in the apartment tower at 245 Dunn, near Queen St. W., shortly after 8 p.m. The building was evacuated while 40 firefighters worked to put out the fire, which was discovered on the 11th floor of the building.
One person was taken from that floor with vital signs absent and taken to hospital.
Four more patients were also helped away from that floor and treated for smoke inhalation, Toronto EMS officials said.
Firefighters said its unclear what caused the blaze at this time.
The building is a Toronto Community Housing Corporation Building that's also home to the Loft program, which helps seniors and older adults who have mental illness or disabilities.