The Walmart in Leamington will open again Wednesday morning after a fire Tuesday night.
Fire officials said the blaze started at around 9:40 p.m., on a section of the roof that was being worked on earlier in the day.
No one was hurt and damage is estimated at around $10,000.
Just half an hour earlier, firefighters were called out to an apartment building on McGaw Avenue.
A woman was taken to the hospital with undetermined injuries.
Careless cooking is blamed for that fire which caused $175,000 in damages.