Masi Oka

The Japanese actor starred alongside Panettiere in Heroes and has fond memories of the star's "beautiful spirit".

Oka wrote on X: "I had the privilege of working closely with her, and I'll always remember her for her beautiful spirit, immense talent, and the joyful energy she brought to everything she did and the people around her.

"She was way wiser beyond her years and now gone too soon... My heart goes out to her family and everyone who loved her. Rest in peace, Hayden."