You can search the Social Security Death Index, which is not the same as a certificate at
http://ssdi.rootsweb.ancestry.com/ or http://www.familysearch.org/Eng/default. once you have located it in the index you would have a better idea of where to either order the death certificate or where to search for it online.
There are other Death Indexes that you can search, most notably the California Death Index 1940-1997 at http://www.deathindexes.com/california/i. . which is the (free version) at Rootsweb.
A Genealogy Guide for Finding Obituaries, Cemetery Burials and Death Records for the state of California can be found at http://www.deathindexes.com/california/i… free and some fee.
Texas death certificates are available on FamilySearch.org on their pilot site at: http://pilot.familysearch.org/recordsear… I believe the project is now complete and I just learned that some Ohio death certificates
are on that site as well. Also, a new beta site on FamilySerch.org has more records at: http://fsbeta.familysearch.org/s/collection/list several states were added.
There are a few websites that have some vital records at no charge. For example, the state of Missouri has death certificates for the years 1910-1958 on their website at: http://www.sos.mo.gov/archives/resources… A few pre 1910 birth and death certificates are also available on the site but all of their records have not been transcribed yet.
There are many other indexes and some that have some actual death certificates online but knowing the time period and state would go a long way toward helping someone locate them. However, there is no centralized location where all death records/certificates that are online can be searched.
Tina · 5 years ago