ST Peter’s Boys School in Creggan is on fire.
It’s believed the fire began just before 9 p.m. tonight.
People at the scene said they believe the roof has fallen in while others said the flames are visible from the Waterside.
This is the second time in three months the school has been attacked since it closed in June. In July the school’s canteen was targetted by arsonists.
Five engines were at the scene tackling the blaze tonight plus an ambulance.
One eye witness said a crowd of more than 100 people were also at the scene.
Recently plans were lodged to build 100 new homes on the site of the school.