What tragedy occurred that year that was second only to her father’s death?

From the text:

Mr. John P. Spaulding, of Boston, died in February, 1896. Only those who knew and loved him best can understand what his friendship meant to me. He, who made every one happy in a beautiful, unobtrusive way, was most kind and tender to Miss Sullivan and me. So long as we felt his loving presence and knew that he took a watchful interest in our work, fraught with so many difficulties, we could not be discouraged. His going away left a vacancy in our lives that has never been filled.