If someone co-signs for an individual to get into an apartment, and does not live with the person in the apartment. Then, years later after the person in the apartment has renewed the lease at least 5 times without the co-signer's consent or involvement, the tenant dies... is the original co-signer in any way responsible for any remaining rent or cleaning fees?
There was presumable a separate co-signer agreement document, so let's take this sample to be representative. In this case, note that it states "This Cosigner Agreement shall remain in full force and effect throughout the term of the lease period regardless of any extensions and/or changes in terms unless specified otherwise in writing by Landlord". That lease would have expired years ago, and with it, the obligation embodied in the agreement; the landlord presumably renewed the lease without a co-signer, in subsequent years. The only imaginable way that a co-signer agreement could still be in force would be if it explicitly said the agreement automatically renews, until terminated in a specific way. There are state laws regarding automatic renewal clauses, so if there is such a clause, then its enforceability would depend on things like not conspicuous the clause is and whether the deadlines are legally acceptable in that state.