Police say an 85-year-old woman was walking through the transit station around 11:15 a.m.  when the suspect approached and punched her in the face.
The woman was knocked unconscious by the force of the impact, but was revived at the scene.  He was then taken to hospital with serious injuries.
The attack was just the latest violent incident to occur at Kipling Station in recent weeks.
On June 17 a woman was allegedly set on fire at the station in what police described as another “random attack”.  That woman was rushed to hospital with second and third degree burns, but succumbed to her injuries earlier this week.
A suspect is facing multiple charges in connection with this incident.
The suspect in Thursday’s incident at Kipling Station is described as a black man in his 30s.  He was wearing a black shirt, black pants, a black toque and a white scarf, according to police.
Police are appealing to the public for help in locating him.