Alexandra Community School in Owen Sound will remain closed on Thursday.
The school and the daycare were closed Wednesday after a boiler explosion shortly after 5 PM on Tuesday.
Fire and health officials want to make sure the air and school environment is safe for students, staff and parents.
Bluewater board Manager of Plant Services Dennis Dick admits the main issue right now is air quality.
He notes the boilers are old enough that some asbestos was used in their construction.
The school may even be closed on Friday.
Investigators from the Ontario Fire Marshall’s office and the Technical Standards and Safety Authority will be at the school again on Thursday.
They will look into what caused the explosion.
But Fire officials stress there is no threat to the rest of the neighbourhood and any contaminants are contained in the school building and will be cleaned.