The historic Strathmartine Hospital could be on its “last legs” after a fire ravaged the building this week.
Angus council is still assessing the extent of the damage, caused by a blaze thought to have been started deliberately on Monday evening.
Local conservation campaigner Karen McCauley, who managed the Strathmartine Hospital Histories project, said she fears the incident could signal the death-knell for the listed building.
The former hospital for people with learning disabilities has been targeted repeatedly by vandals and fire-raisers, and is currently up for sale with plans to redevelop it into housing.
Karen said: “From a safety perspective, it has got to the point where the building may have to be taken down to just one level.
“The building has been left decaying for years and plans to redevelop it have been pending for several years.
“I don’t know how much longer the building will hold up. It could be on its last legs after this latest incident.”
It took firefighters over two hours to extinguish the blaze on Sunday night and police are investigating the circumstances.
The Scottish Fire and Rescue Service have issued a safety warning about the building.
A spokesman said: “We have found from experience and intelligence that unoccupied buildings can be targeted by malicious fire-raising.
“We would urge the owners of derelict properties, wherever possible, to ensure that they are properly secured to help minimise risk such as unnecessary fires.
“Structures such as these have the potential to cause great risk to members of the public who are thinking of entering them for any reason.
“For younger people, these structures can appear to be an area for adventurous play, however the danger of harm is very real.”
The hospital was sold by NHS Tayside in May 2005 and is now owned by Heathfield Ltd.
A spokesperson for NHS Tayside said: “Along with security and protection of the site, the current planning application sits with the owner, Heathfield Developments. The development of the site does not hinge on any potential financial obligation to NHS Tayside.”
Heathfield’s representatives, Muir Smith Evans, could not be reached for comment at the time of publication.
An Angus Council spokesman added: “The site is regularly visited by staff from Building Standards to ensure the owner is taking ‘reasonable’ steps to ensure that all buildings considered a ‘danger’ are boarded up and not readily entered by unauthorised visitors to the site.
“Any work sought by us is readily carried out by the owners of the site who have the ultimate responsibility to ensure the site is safe.”