Owners dispute duty to rent-free tenant

Who's responsible for making repairs inside apartment?

Q: I live in a 12-unit apartment building. When the previous owner died, his will provided an apartment "rent-free for life" to a friend of mine. The building was sold recently and the new owners are aware of the agreement and do not collect rent from this tenant. But an issue has come up and I am wondering who is legally responsible for the maintenance inside this rent-free apartment?