Damage is estimated at over $500,000 following a fire on Lanark Crescent last week.
Firefighters rushed to the structure fire, in the neighbourhood just south of Great Lakes High School, over the noon hour on Wednesday, June 12.
Sarnia Fire Rescue Public Education Officer Mike Otis said the cause was deemed accidental.
He previously told Sarnia News Today no one was home at the time.
The fire impacted three separate units of a row house.
A dog was rescued and a firefighter suffered a "mild injury" while working at the scene.