India, Aug. 17 -- Actor Hayden Panettiere has died at the age of 36. She was best known for her roles in popular television series including "Heroes" and "Nashville."

According to TMZ, Panettiere died earlier Sunday. She and her on-and-off boyfriend, Brian Hickerson, had reportedly flown from Los Angeles to the South on Saturday.

Law enforcement sources told TMZ that police responded to an incident involving Panettiere on Sunday. An investigation is ongoing, and her cause of death has not been revealed.

Panettiere's father, Skip, confirmed her death in a statement provided to ABC News.

"It is with profound sadness that we share the tragic passing of our beloved Hayden. She was an incredible light and a force of nature who brought imme...