The narrator's mother's first husband was Harry Avalon, the performer. He died in the trapeze accident. The narrator's mother's second husband is the narrator's father. The mother met this man while she was in the hospital, following the accident. They married and lived on a farm. The narrator refers to his death, but gives no details about how he died. Given that he and his wife (narrator's mother) were older, he may have died from natural causes or something relating to old age. 

The narrator notes that she owes her life to her mother three times. The first time is when the mother saves her during the circus accident. The second time is when her mother is in the hospital and meets the man who would become her second husband, and the narrator's father. While in the hospital, her mother learns to read and this becomes a huge part of her life from then on. The third time the mother saves her daughter is when she leaps to the window to pull her daughter out of the house fire. The narrator flashes back to these memories and sporadically comes back to the present. In the present, she adds that she has come back east to live with her mother and read to her, following her father's death: 

Since my father's recent death, there is no one to read to her, which is why I returned, in fact, from my failed life where the land is flat. I came home to read to my mother, to read out loud, read long into the dark if I must, to read all night.

Again, the narrator gives no specific reason as to why or how her father has died.