In one of her final interviews with parenting outlet Momé, she discussed her experiences with a traumatic childbirth, postpartum depression and alcohol dependency.
“I’m a warrior. I’m a woman who has been through more trauma than I ever thought I’d face, but I’m resilient,” she said.
“I’m a work in progress – we all are. I take each day as it comes. I’m doing the work, and I’m doing my best.”
Panettiere said she had turned to alcohol while struggling with undiagnosed postpartum depression.
“I turned to wine, which ultimately ended up leading to an alcohol dependency. It was how I would get through each day.”
She finished with a heartfelt message to other mums: “You’re stronger than you know. And you’re going to be just fine”.
Panettiere’s death was announced today by her father Skip Panettiere, who described the loss as “tragic”.
“She was an incredible light and a force of nature who brought immeasurable love and joy to all who knew her – and to the millions who watched her onscreen,” he wrote.
Her cause of death has not been disclosed.
She is survived by her daughter, Kaya, 11, whom she had with former fiance, Ukrainian boxer Wladimir Klitschko.
Kaya has lived with her father since the couple split in 2018.
As she promoted her memoir, Panettiere spoke candidly about her life and struggles away from the screen.
Hayden Panettiere as Kirby Reed in a scene from Scream VI. Photo / Supplied
“I felt nothing,” Panettiere told Momé of her depression after Kaya’s birth.
“And now I had to figure out how to bond with her. It seemed like an impossible task.
“I had always heard that moms feel an instant rush of love, but I didn’t – and I had no idea why.”
Hayden Panettiere with her friend and photographer Randall Slavin. Photo / @haydenpanettiere
On July 27, she shared what would become her final Instagram post, a black-and-white photograph of her smiling with friend and photographer Randall Slavin.
“Good times and good friends,” she captioned the image.
The post has since drawn messages from friends, fellow actors and fans.
Selma Blair shared her grief in comments on Panettiere’s most recent Instagram post.
“I love you. Don’t be gone. Don’t be gone. Please. Please,” she wrote.
Eleven minutes later, she added: “I love you whale tail my friend.”
Slavin also returned to the photograph after her death, sharing a brief tribute to his friend: “Peace be with you, H”.
Panettiere’s first on-screen appearance was in a commercial in 1990 aged just 11 months old, launching a decades-long Hollywood career.
She was best known for playing Claire Bennet in the hit series Heroes and Juliette Barnes in the musical drama Nashville.
Her film credits included Remember the Titans, Raising Helen, Ice Princess and Scream 4.
TMZ, citing law-enforcement sources, said police responded to an incident involving Panettiere over the weekend and an investigation remained open.