Two prefabricated classrooms have been burned and 63 windows broken at St Joseph's Presentation College, in Lucan, Co Dublin. It is believed the fires, notified to gardai at 1.30 a.m. yesterday, were started deliberately. Damage has been estimated at up to £80,000. Gardai believe local youths may be responsible. On July 12th, last, petrol was poured into the local Presbyterian church and set alight, causing considerable damage.