Four people were taken to hospital after a basement apartment fire in Toronto’s west end early Tuesday morning.

Emergency crews were called to a home on Boustead Avenue, near Dundas Street West and Bloor Street West, at around 3:15 a.m.

Police say a 16-year-old boy suffered serious injuries and was transported to hospital. His injuries are not considered life-threatening. Three other family members, a 51-year-old man and two boys aged 14 and 11, were also taken to hospital after being exposed to smoke.

The cause of the fire remains under investigation.