Ennis fire service was called to a fire at the old Ennis National School twice overnight.
The roof of a shed at the old school on the Kilrush Road collapsed in what was the second suspected arson attack at the unoccupied site in twelve months.
Five units of the fire service including a hydraulic platform and water tanker dealt with the blaze for over an hour before crews were called back to the scene in the early hours of the morning to extinguish smouldering embers.
The school was targeted in a similar incident in June of last year.
While Ennis fire service dealt with last nights fire, Shannon fire brigade had to be called in to deal with a chimney fire in the Oak Park area of Ennis.
Meanwhile, on Tuesday, Shannon fire service was also called into action in Limerick City when they spent several hours dealing with a house fire on the North Circular Road.