You will have to order the record yourself for death certificates after 1920. Ancestry has an index of deaths after 1971. Do you have the exact dates of death?
I see an entry on www.findagrave.com, that says there is a Lillian and a William Blossey, buried in Gresham cemetery, Vermontville, Eaton County Michigan, but there are no dates. You could try contacting the cemetery to see if there is more information. If you get exact death dates, then you can post a message here to ask for an obit lookup.
If you decide to order death records, it is slightly cheaper to order them from the county than from the state, but you need to be sure they died in Ingham County. Here is the link
http://cl.ingham.org/Portals/CL/Documents/Death%20CERTIFICAT...

In the meantime, you might search for them at www.familysearch.org When I put in William Albert Blossey, there was a birth in Illinois that might be him, and it listed his parents.