A major fire has broken out at the former Convent of Mercy in Skibbereen, extensively damaging the building and causing the church roof to collapse.
Residents in the immediate vicinity are being asked to remain indoors and close all doors and windows.
Cork County Fire Service was alerted to the blaze at 4.07pm with Fire Brigade units from Skibbereen, Schull and Bantry all scrambled to the scene at North Street close to the town centre.
A water tanker from Bantry and an Aerial Platform from Midleton were also mobilised to the incident.
Elderly residents living in nearby flats were evacuated due to fears of smoke inhalation but no injuries have been reported.
Garda traffic diversions are in place and the public are asked to avoid the area.
The cause of the fire has not yet been confirmed.
The convent buildings were vacant for more than 20 years after the Sisters of Mercy, which had been based at the convent for more than 140 years, moved to smaller premises.
Last week, Cork County Council granted permission for the €10m redevelopment of the site.
Remcoll 3 Ltd had applied to Cork County Council to revamp the former convent, a protected structure, in order to build apartments and commercial facilities on the site.
Under the plans, the chapel would be revamped into commercial facilities, including a multipurpose room and space for hot-desking, and the former Mercy convent would be converted into seven apartments.
The former Mercy Heights School would be converted into office space, and a new four-storey apartment block would be constructed on the south-east of the site, incorporating some 52 apartments.
Planning was granted, subject to some 22 conditions, including the removal of one apartment in the former convent, and the preparation of a number of new roads and mobility plans.