It has always been my impression that all of the county institutions were, at one time, located together at Snake Hill. That would include the alms house, the hospital for communicable diseases (mostly TB), the minimum security prison, insane asylum,etc. Is it possible that your relative may have contracted TB? It was so prevalent in those days.
Recently, the state has become very guarded about disclosing cause of death and many people have complained that this information is not shown on copies of death certificates. This new policy has to do with the AIDS epidemic and privacy issues.
Many people - especially those who are pursuing family history are perplexed by this but it appears that little can be done to reverse the new policy.
Hope you are successful in finding the information you are seeking. Good luck!