A fire at the derelict Down hospital is being treated as arson.
Police were called just before nine on Monday night to the building in Pound Lane.
Three fire engines were on the scene.
It's been reported a number of youths were seen at the building earlier that evening.
Police are asking witnesses to call 101.
£8m to improve access to dentists announced by Health Minister
Fire at derelict hotel being treated as deliberate, police say
Man injured after house and three vehicles set alight in Co Antrim
IT system for Northern Ireland schools ‘largely restored’ following cyber attack
£100 home heating oil grant to be paid out by ‘summer at earliest’