Co-stars and friends of Hayden Panettiere are remembering the actor for her friendship, intelligence and talent after her shocking death at age 36 on Sunday. 

Panettiere, who had already appeared in dozens of commercials by the time she was 5 years old, starred in “Remember the Titans,” “Heroes,” “Bring It On,” “Nashville” and more.

“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,” her father, Skip Panettiere, said in a statement sharing the news of her death Sunday.

“I’m crushed,” Bethany Joy Lenz, who starred in “Guiding Light” with Panettiere in the late ’90s, wrote in a lengthy post on Instagram. 

Lenz recalled knowing a young Panettiere, running through the hallways of the studio where they filmed, “laughing and playing games in between blocking and camera rehearsals.”

“She knew her lines and everyone else’s. Her intelligence was astonishing. She understood scenes and nuance and human struggle like no child I’d ever seen on camera. And she’d sit with you for a great conversation, then giggle and go play,” Lenz wrote. 

Lenz said she and Panettiere connected “on and off over the years.”

“I always felt such joy seeing her when we were lucky enough to cross paths,” she said. 

Kelly Osbourne, who called Panettiere “such a good friend to me,” wrote on an Instagram story that she is deeply saddened by the loss. 

“We understood each other in a way few truly can—recognizing how difficult it is to grow up in the spotlight, and how isolating it can feel even when surrounded by so many people,” she wrote. “I will never forget you, Hayden, and I will always believe you deserved better.”

Osbourne guest-hosted an episode of “Red Table Talk” in 2022, in which Panettiere discussed her struggles with addiction, postpartum depression and giving up primary custody of her daughter. 

Panettiere had recently spoken out more about those hardships, including on “CBS Mornings,” around the May release of her memoir, “This Is Me: A Reckoning.”  

One of those emotional conversations, in which she also spoke about the death of her brother in 2023, was on the podcast “On Purpose with Jay Shetty.” 

Shetty reacted to Panettiere’s death Monday, writing in a comment on Instagram, “Truly heartbroken by this news.” 

“I can’t believe it. Our friendship had just begun and I was so moved by the conversation we shared earlier this year. My love and condolences to her family and fans,” he wrote in another comment. 

Viola Davis, who starred with Panettiere in the 2016 film “Custody,” called her “an amazing talent.”

“An old, wise soul with such a deep heart,” she wrote in a post on Instagram. “I wish the world had more time with you because I had a burning curiosity about who you were becoming. I saw this beautiful Phoenix rising from the ashes. Your tests became your testimony, and your testimony became your legacy. You will be remembered.”

Bryan Fuller, a writer for “Heroes,” said Panettiere was a muse.

“Wise beyond her years and already saddled with so much of a life, she left an indelible mark on me as a writer and a storyteller,” he wrote on Instagram.

Other celebrities shared their grief in comments on social media. 

“I love you. Don’t be gone. Don’t be gone,” Selma Blair wrote. “Please. Please.”

“I love you Hayden,” wrote David Arquette, who starred with Panettiere in “Scream 4.”