Old building, condo unit wear and tear. Does association need to fix it?

Is the condo association required to replace cracked or falling off plaster and/or drywall if the issue is not related to a problem with the common elements? A unit owners bedroom ceiling is cracked and falling down. The problem is not related to any issues with water leaks or any other common area problem. The building is about 100 years old and the plaster is original to the building and is old. Who is responsible to repair the ceiling in the bedroom? Is it an insurance claim and if so by who, the unit owner or the condo association?