Windsor police are now investigating a house fire in downtown Windsor.
The fire broke out last Thursday afternoon in 700-block Pelissier Street.
Police say when officers arrived, they found heavy smoke and flames coming from the building.
A 43-year-old man with significant burns was taken to hospital for treatment.
The man is in a Hamilton hospital and police describe his injuries as life-threatening.
Investigators with the Ontario Fire Marshal Office were called to investigate but have since left the scene.
Monday morning, Windsor Fire & Rescue posted on social media, saying the fire caused roughly $90,000 in damages and believe the fire originated on a mattress.
Anyone with information is asked to call Windsor police or Crime Stoppers.