A woman was rushed to hospital with life-threatening injuries after an overnight fire at an East York highrise building.

The fire broke out in a second-floor unit at a building on Donlands Avenue, near Cosburn Avenue at around 12:30 a.m.

A woman believed to be in her 60s was rushed to hospital via emergency run, Toronto Paramedic Service said.  

Fire officials at the scene told CP24 that the woman sustained burns to approximately 30 per cent of her body.

The cause of the fire has not yet been determined, but fire officials said smoking is being examined as a possibility.

The Ontario Fire Marshall’s Office has been called in to investigate.