Sendhil Ramamurthy shared memories of his first time meeting Panettiere during auditions for the superhero drama

Tributes from Hayden Panettiere’s co-stars across television and film have been streaming in following her death at 36 on Sunday.

Actor Sendhil Ramamurthy, who played Mohinder Suresh on the NBC sci-fi series Heroes, remembered the actress in a heartfelt post on Tuesday. Panettiere featured as the virtually invincible high school cheerleader Claire Bennet on the series across four seasons.

“This is such a rough one,” Ramamurthy began. “The 1st time I met Hayden was at the final screen test for Heroes. I was so nervous I was sweating through my shirt b4 I even got there. I went straight to the bathroom to compose myself and then went to sign in, expecting to find a bunch of fellow nervous-as-hell actors.” Instead Ramamurthy found Hayden, who was “belting show tunes in the waiting room” and didn’t have a single “nerve in sight.”

The actress was “already a pro,” Ramamurthy recalled, adding that he “learned a lot from her” during their time together. He also highlighted how Panettiere would treat others. “She stuck up for background actors when they were mistreated, knew every crew members name, and was so generous with her time,” he said.

Ramamurthy shared a photo taken of himself and the actress in Vegas the day after the Golden Globes. “We had to do press and I wasn’t feeling well. Hayd kept going on and on at me about drinking fluids and made sure I had plenty of Gatorade,” he said. “That’s how I will remember her: a kind, joyful, professional, shi*talker, who even at a young age, understood the importance of hydration. Sending love to her family, friends, and my fellow cast mates, RIP Hayd. You will be missed.”

Panettiere’s turn as Claire Bennet on Heroes was among her most memorable roles. In a Rolling Stone feature looking back at the actress’ six essential performances, culture writer CT Jones said: “Panettiere remained the focus of the story, turning out measured and determined performances that grounded audiences in the often confusing world of magic powers and evil government agencies. ‘Save the cheerleader, save the world,’ wasn’t just a powerful rallying cry. It’s a legacy.”