Police are investigating a blaze at a derelict hospital near Dundee which was started deliberately.
Fire crews were called to the site of the old Strathmartine Hospital just before 19:00 on Sunday.
The site, which was also previously an orphanage for people with learning difficulties, has been empty for 15 years.
Police are following a positive line of inquiry but appealed for anyone with information to contact them.
They believe the fire was started between 18:00 and 19:00.
The building has been regularly vandalised.
A police spokesman said: "This is one of a number of empty and derelict buildings in and around Dundee, many of which are hazardous environments.
"People place themselves at risk if they enter these buildings, climb on scaffolding or on the roofs, and especially if they are reckless enough to start fires.
"They are boarded up for a reason and are potentially unsafe, may possibly contain hazardous materials such as asbestos, or be structurally unsound."
The spokesman added: "It goes without saying that if this fire had taken hold quickly, the person or persons who started it could potentially have been trapped inside, with obvious dire consequences. They have put lives at risk, most obviously their own."