Sarnia's St. Clair High School was closed Tuesday because of an odour that resulted in complaints of headaches and sore throats from some of the occupants of the building.
The Superintendent of Business and Board Treasurer Brian McKay says monitoring by Sarnia fire officials and investigation by Union Gas ruled out a natural gas leak.
He says tradespeople remained in the building trying to determine the source of the odour.
The school was closed late Tuesday morning and staff and students were sent home.
According to a tweet by the school, St Clair is open today (Wednesday), air assessments are complete and they have been given the all clear.
