Panettiere, 36, died Sunday at a residence in Greenville, South Carolina.
Disney pulled back the curtain on some of its biggest projects at D23, including the first official X-Men cast reveal, a new Ryan Gosling-led Star Wars film and updates on fan-favorite animated franchises.
Panettiere shared a daughter with heavyweight champion Wladimir Klitschko.
Actress Hayden Panettiere was found in cardiac arrest prior to her death, the Greenville County Coroner's Office said in a press release Monday.
Nick Reiner is accused of fatally stabbing his parents at the family's home.