Wladimir Klitschko in 'profound shock' over death of ex Hayden Panettiere

Former boxer Wladimir Klitschko said his family is "going through a time of profound shock and grief" following the death of his ex-partner Hayden Panettiere.

The Nashville and Heroes actor, aged 36, who was the mother of their daughter Kaya, died on Sunday after a reported cardiac arrest.

Police said there were "no signs of foul play or suspicious circumstances", while the Greenwood County Coroner's office confirmed there were "no signs of trauma". Investigations remain ongoing.

In a memoir published earlier this year, Panettiere opened up about her difficulties with mental health and the loss of her younger brother, Jansen, who died of a heart condition in 2023, aged 28.

She also talked about her decision to give full custody of her daughter to Klitschko.

In a post on Instagram, Klitschko wrote: "The announcement of Hayden’s tragic death saddens me deeply. She left this world far too soon. Hayden was, although no longer my partner, an important part of my life and the mother of our daughter, Kaya.

"She built an incredible career through immense talent, while also facing the darker sides of a very demanding industry. Nothing will erase the times we shared or the place she had in our lives."

He also extended his "deepest condolences" to Panettiere's parents, friends and fans.

"To our daughter Kaya," he continued, "I will always speak of her mother with respect and make sure she remembers the person she was."

In her memoir, Panettiere said her daughter had lived with her father full-time from a young age amid her struggles with addiction and mental health.

She said: "I was struggling with mental health and anxiety and the postpartum and having to act my way through it and just feeling like I completely lost myself."

Emergency crews responded to a 911 call from an acquaintance of Panettiere about a "reported cardiac arrest" in Greenville on Sunday afternoon, the coroner’s office said.

The California resident was found unresponsive inside the South Carolina apartment complex "where she had been temporarily staying".

First responders tried to resuscitate her, although this was unsuccessful, and she was pronounced dead at the scene.

Her official cause and manner of death are still pending the results of additional testing.

Tributes pour in following Panettiere’s death

A statement from Panettiere’s representatives said the star will be remembered by her family as an "incredible light" who brought "immeasurable love and joy to all who knew her".

Her Nashville co-star Connie Britton was among those "heartbroken" by the loss.

Britton said she had "no words" after Panettiere's death, hailing her as "bursting with brilliance".

The Emmy-nominated actress, who appeared alongside Panettiere in the US drama for nearly five years, shared images of the pair on set.

"This was Hayden. Bursting with brilliance, shining so bright," she wrote.

The 59-year-old actress, also known for Friday Night Lights and American Horror Story, continued: "I have no words for this sad song. Just heartbreak."

Charles Esten, who played Deacon Clayborne on Nashville, recalled the first time he met Panettiere in a lengthy social media tribute.

"We became fast friends, working very hard to play those 2 troubled Nashvillians, but always having fun and laughing a whole lot along the way," he wrote.

"She was, of course, extraordinarily talented, infusing her larger-than-life character with all the heart, charisma, humour, whip-smart intelligence, and flat-out magic that were, alongside whatever troubles and pain she carried, a part of her own personal palette."

Panettiere, who played Kirby Reed in Scream 4 and Scream VI, was remembered fondly by co-stars from the horror franchise.

Emma Roberts, who appeared alongside Panettiere in films such as Scream 4 and The Architect, shared snaps of the two sharing an embrace.

Roberts wrote: "Rest in peace my sweet friend. You are so loved and will be forever missed."

Nico Tortorella, who also appeared in Scream 4, said: "I keep trying to write something, but there are too few words for you."

Beneath a photo of himself with Panettiere, the 38-year-old actor added: "I love you, I miss you and I’m sorry."

Kim Cattrall, who starred alongside Panettiere in Ice Princess, shared a picture of her with "sweet Hayden" and said she was "gone far too soon".

Actor Tim Allen said in a post on X: "I am shocked and so sad as the passing of Hayden Panettiere. She played my daughter in the movie Joe Somebody. The fondest memories of that movie were moments around her. She is a wonder and my prayers are with her family."

Brittany Snow, who played Panettiere’s on-screen sister for three years in the TV show Guiding Light, posted a throwback photo of the pair as children to her Instagram stories, captioning it: “I was lucky enough to play your sister for 3 years.

"I related to you so much in so many ways. Ways that I never even told you. Your talent was remarkable & so was your determination to be a bold, bright shining light. And you were."

She said Panettiere was "always supportive, curious, funny and brave", adding: "You will always be remembered undoubtedly for your undeniable strength and spirit."

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Panettiere started acting as a child, appearing in soap operas before gaining wider recognition for her role in the 2000 sports drama Remember the Titans, alongside Denzel Washington and as the voice of Dot in Pixar’s 1998 film A Bug’s Life.

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