The U.S. Embassy and Consulates cannot issue replacement or certified copies of U.S. birth certificates, death certificates, or marriage certificates. You can apply for a copy or request an amendment through the Vital Records Office in the state in which the death occurred: https://www.cdc.gov/nchs/w2w/index.htm

Information on how to obtain vital records in Italy is available on the Embassy’s website at Additional Resources for U.S. Citizens - U.S. Embassy & Consulates in Italy .