In February 1901, Harrison fell ill with what was first thought to be influenza but later confirmed as pneumonia. Despite treatment, his health declined, and he died at his Indianapolis home on March 13, 1901, at age 67, according to the data on Wikipedia.
His reported final words were, “Are the doctors here? Doctor, my lungs …” He was interred at Crown Hill Cemetery in Indianapolis beside his first wife, Caroline. Following her passing in 1948, his second wife, Mary Dimmick Harrison, was also laid to rest alongside him.