Cemeteries are often an excellent source of information about the death of an individual, not just an interment. In the absence of a death certificate, cemetery records may be one of the only sources of the cause of death.
I have pursued either visiting or writing to cemetery offices and requesting information from their interment ledgers/books. Interment books, sometimes referred to as day books, are typically organized by the date of interment (not death), and include the name of the individual, the gender and age, sometimes the address, and always the cause of death and the duration of the final illness. This little-used historical and genealogical resource can be invaluable. I have seen entries for U.S. Civil War casualties that also listed the date of death, the place at which the person died, and the exact cause of death. A bullet through the chest, perforating the lung; killed in a fall from horse; dysentery; smallpox; and many other exact causes of death for soldiers are listed that may not appear in the individual’s military service records.