Weeks before her death at age 36, Hayden Panettiere completed a campaign for People for the Ethical Treatment of Animals (PETA) advocating for the freedom of whales and dolphins. The ad was released Tuesday, showing the actress in a bathtub, drawing a parallel between her confinement and the lives of marine animals in theme park tanks.

"Imagine spending your entire life in a bathtub. That's what it's like for dolphins and whales in tiny tanks at marine amusement parks," Panettiere stated in the ad. "We can end this, you and me."

She added, "Can you imagine their frustration, their trauma, their depression? All that is important and crucial for their wellbeing is ripped away."

Panettiere, known for her roles in "Heroes" and "Nashville," was found dead on Sunday at an Airbnb in Greenville, South Carolina. A police report indicated no signs of trauma contributing to her death, which is being investigated as a suspected overdose. Her on-off boyfriend, Brian Hickerson, was present at the scene. Panettiere would have turned 37 on Friday.

PETA released the clip on Tuesday, showing the actress posing in the bath as a comparison to the constrained lives that marine wildlife lead in captivity

This advocacy work continued a long-standing commitment to animal rights. At 18, Panettiere participated in the documentary "The Cove," which criticized dolphin hunting in Japan. She joined activists in a protest in Taiji and spoke out against what she called "outdated, senseless cultural traditions." She told E! News at the time, "I'd do it again."

Panettiere's passing comes after a struggle with alcohol and opiates. In 2020, she entered a rehabilitation program for eight months after a doctor warned her that continued drinking could be fatal within five years. She also relinquished custody of her daughter, Kaya, then 11 years old, to her father, Ukrainian boxer Wladimir Klitschko, to focus on her recovery. Panettiere described the separation from her daughter as "the most gut-wrenching experience of my life."

Her memoir, released before her death, also detailed her strained relationship with her mother, Lesley Vogel, who had been her manager during her childhood.

Panettiere's "Sleepwalker" co-star Justin Chatwin reflected on her perceived loneliness during the filming of their last movie together last year. He noted that while she was a sweet and authentic person, he sensed she was struggling. "I know this world of addiction, and Hollywood - it takes, and it takes from youth," Chatwin commented, suggesting that struggles can stem from both personal and professional environments.