The fire which threatened to take hold of a secondary school in Co Louth may have been thwarted by a participant in the suicide awareness Darkness Into Light walk on Saturday morning.
The blaze destroyed a wooden building that housed a study hall and classroom at the rear of the St Louis Secondary School complex on the Castletown road, Dundalk.
Firefighters prevented it from spreading to the adjoining main school building and fought the blaze for nine hours.
Senior assistant chief fire officer for Louth Robert Page said "the fire was in one of the older buildings at the rear of the school and was well ablaze and beginning to spread to the main school building," when the fire crews arrived close to 3am. "Station officer Paul Kelly ensured it did not spread to the main school building and was contained."
Three fire tenders responded, one from Ardee and two from Dundalk.
Mr Page said a member of the public raised the alarm at 2.52am. It is believed that people on their way to take part in the Darkness Into Light walk in Dundalk may have also seen the flames and raised the alarm.
Meanwhile gardaí said it could be Tuesday before it is safe to examine the scene.
A spokesman said “the cause of the fire has not been identified” which is due to substantial damage to the building.
Acting school principal Michelle Dolanthanked the emergency services and said every staff member would be on hand to help students continue to prepare for summer exams. The school hopes to open as normal on Monday.
