Damage is pegged at $800,000 after a house fire on Menard St. in east Windsor.
Fire fighters were called to a home in the 9700 block near Martinique Ave. around noon on Monday.
It took crews about an hour to put out.
An investigator with the Ontario Fire Marshal's Office was called in to assist with the investigation.
The investigation determined the fire started in the laundry room but could not determine what started the blaze.
The cause has been listed as accidental.
A resident remains in hospital and is being treated for smoke inhalation.
The resident is in critical condition.
Menard fire investigation is complete, accidental started in laundry room, cause undetermined, damage is $ 600,000 structure $200,000 contents and exposures, resident is still critical, being treated for smoke inhalation.*JL
— Windsor Fire (@WindsorFire1) January 23, 2019