Actress Hayden Panettiere, best known for her roles in "Heroes" and "Nashville," has died at the age of 36, according to reports from TMZ. The news outlet cites sources close to the star, stating Panettiere passed away on Sunday. Law enforcement is currently investigating a potential incident surrounding her death, though details remain scarce. A representative confirmed the news to ABC News, expressing deep sadness. While the cause of death has not been officially released, the ongoing investigation suggests the circumstances are not straightforward. Panettiere's career spanned both television and film, earning her recognition and a dedicated fanbase. Further updates are expected as the investigation progresses and more information becomes available.