The cause of a commercial fire in Leamington has been ruled accidental.
Chief Andrew Baird says damage was contained to the roof and the cause of the fire was likely electrical.
One person sustained minor injures when tar dripped down from the roof when the fire broke out, according to Baird.
Damage is estimated at $450,000, but Baird says that total might change after insurance adjusters finish their assessment.
The fire caused the cancellation of the afternoon and midnight shifts at the plant.
Unifor Local 444 President Dave Cassidy says work resumed Friday morning.