Detectives are today hunting vandals who went on the rampage at the North's first inter-faith school.
About £20,000 (€29,300) worth of damage was caused to Belfast's Lagan College in the overnight attack.
The integrated school blazed a trail of reconciliation in the early 1980s as the first to educate both Protestants and Catholics together.
The Police Service of Northern Ireland (PSNI) said they have yet to establish a motive for the vandalism spree.
Several windows were smashed, portable buildings were broken into and computer monitors were broken, said a PSNI spokeswoman.
Detectives from Castlereagh are treating the incident at the Manse Road, Carryduff premises as burglary.
They have appealed for anyone who noticed anything suspicious or has information about the attack, reported at 12.30am, to get in contact.