Acute surgery cases at Dunedin Hospital were suspended on Sunday after a steam leak caused a tile to fall into a sterile storage room.
Only life-threatening cases could be operated for about two hours after the incident.
The area had been recently ''redeveloped'', meaning potential asbestos contamination was not an issue, chief operating officer Lexie O'Shea said in a statement.
''On Sunday one ceiling tile came out of the suspended ceiling within the operating theatres sterile store due to a steam leak.
''The leak was caused by a union joint failing on a steam pipe in the plant room directly above the sterile store.
''The area has been recently redeveloped so any asbestos materials within the ceiling had been totally cleaned as part of these works.''
All of the equipment in the room had to be re-sterilised.
''Acute cases that were not time critical were held for approximately two hours while the ceiling tile was repaired and a thorough assessment of the facility and equipment was undertaken,'' Mrs O'Shea said.
Operating theatres are in the clinical services building, which was said to be ''crumbling'' in a strategic assessment released recently as part of the hospital redevelopment proposal.
The board is carrying out various deferred maintenance projects and asbestos containment work in the building in order to keep the building running until it is replaced.
