Bethany Joy Lenz

The One Tree Hill actress – who had known Panettiere since she was a child actress – said she was "crushed" by her passing.

Lenz wrote on Instagram: "I knew the wild little blonde. Was she nine? Ten? I was eighteen. She ran through the Screen Gem studio hallways at 222 E44th St. laughing and playing games between blocking and camera rehearsals.

"Long, unruly curls trailing behind her. 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, the giggle and go play."

She added: "It's too young and there's still so much more life. And her daughter... Hayden, you are surround by love. I'm sorry for every moment I didn't reach out or check in. This can't be real."