https://secure.apps.state.nd.us/doh/certificates/deathCertSe...ELLWEIN, HUGO, died 02/12/1919, county of death Burleigh County ND, MALE, age 10 Years, born 11/17/1908, county of residence Mercer County ND
You should check out the date range of 01/01/1910 to 12/31/1919. Two infant girls are listed that would not appear on any census.