Azro's death was caused by blood poisoning received when he cut his arm with a corn knife. See sources.
1880 census Hutton Twp, Coles, IL: Adam Cox, aged 39, farmer, bp IL, father VA, mother KY; Mary aged 37, bp IL, father NY, mother SC; Charles W. aged 17; Orval aged 13; Luella aged 11; Claudus C. aged 9; Azro aged 7; and Almarinda aged 5 -- all born IL. Also in the household is a nephew, James W. Cox, aged 23, bp IL, both parents IL. Also a servant, Mary E. McNary, aged 39, and her son John H. McNary aged 3 months.