In the weeks since her sudden passing, questions have continued to surround the circumstances of her death.
Now, the Greenville County Coroner’s Office has provided a significant update as investigators work to establish what caused the actress’s death.
Who was Hayden Panettiere?
Panettiere spent almost her entire life in the public eye after beginning her career in commercials when she was just 11 months old.
She went on to appear in several television shows as a child before gaining wider recognition through films such as Remember the Titans, Raising Helen and Ice Princess.
However, she became best known for playing cheerleader Claire Bennet in the hit superhero drama Heroes.
Panettiere later starred as country singer Juliette Barnes in Nashville, a role that earned her two Golden Globe nominations.
She also appeared in the Scream franchise as fan-favourite character Kirby Reed, first joining the series in Scream 4 before returning more than a decade later in Scream VI.
Away from acting, Panettiere was a mother to her 11-year-old daughter, Kaya, whom she shared with former professional boxer Wladimir Klitschko.
Behind her successful career, the actress experienced a number of deeply difficult periods in her personal life.
She previously spoke openly about suffering from postpartum depression following Kaya’s birth in 2014, as well as her struggles with alcohol and op*oid addiction.
Panettiere later entered rehabilitation and signed over full custody of Kaya to Klitschko in 2018 while struggling with addiction and postpartum depression.
She subsequently described the decision as one of the most heartbreaking experiences of her life.
Her life was struck by further tragedy in 2023 when her younger brother, actor Jansen Panettiere, died unexpectedly at the age of 28.
His family later revealed that he had died due to an enlarged heart and complications involving the aortic valve.
Earlier this year, Panettiere released her memoir, This Is Me: A Reckoning, in which she opened up about childhood fame, addiction, recovery, domestic abuse, grief and the pressures she faced throughout her career.
Her relationship with Brian Hickerson
Panettiere began an on-again, off-again relationship with Brian Hickerson in 2018.
Their relationship was marked by allegations of domestic violence, which Panettiere later discussed publicly and addressed in her memoir, This Is Me: A Reckoning.
Hickerson was arrested on multiple occasions in connection with alleged violence against the actress.
In 2021, he pleaded no contest to two felony counts of injuring a spouse, cohabitant or girlfriend. He was sentenced to 45 days in county jail, four years of formal probation and 52 domestic violence classes.
Despite their difficult history, Panettiere and Hickerson later reconnected and were reportedly involved in each other’s lives again before her death.
Tributes paid to the actress
Panettiere’s death prompted an outpouring of grief from fans, friends and former co-stars.
Her father, Skip Panettiere, confirmed the devastating news in a statement shared on behalf of the family.
“It is with profound sadness that we share the tragic passing of our beloved Hayden,” he said.
The family remembered her as an ‘incredible light’ and a ‘force of nature’ who brought happiness to those who knew her and the millions who watched her onscreen.
Actress Viola Davis, who appeared alongside Panettiere in The Architect and Custody, described her as an extraordinary talent with a ‘deep heart.’
She added that she wished the world had been given more time to see who Panettiere was becoming.
Selma Blair left an emotional comment beneath Panettiere’s final Instagram post, writing: “I love you. Don’t be gone.”
Her longtime friend Bethany Joy Lenz also shared her disbelief, saying it had appeared as though Panettiere was beginning to turn her life around.
Panettiere’s former partner Klitschko remembered her as someone who brought light into the world, adding that she had left it far too soon.
What happened to Hayden Panettiere?
Emergency services were called to the Judson Mill Lofts in Greenville shortly before 2pm on August 16.
Panettiere had reportedly been staying temporarily at a residence inside the building when she was discovered unresponsive.
First responders found the actress in cardiac arrest and immediately began CPR and advanced life-support measures.
Despite their efforts, they were unable to revive her, and she was pronounced dead at approximately 2:32pm.
A responding police officer spoke to Brian Hickerson and his brother, Zach, who were both at the property.
According to the police report, Brian showed the officer a bag containing medication he said Panettiere had been taking. Details identifying the medication were redacted from the publicly released document.
Investigators subsequently obtained a search warrant and examined surveillance footage connected to the property.
Emergency dispatch audio reportedly contained a reference to a possible overdose while CPR was being performed.
The US Dr*g Enforcement Administration has also reportedly assisted the Greenville Police Department with its investigation.
However, authorities have not suggested that a crime took place, and preliminary enquiries uncovered no evidence of suspicious circumstances.
Cause of death update revealed
An autopsy was carried out the day after Panettiere’s death, with Greenville County Coroner Mike Ellis confirming what examiners discovered.
Officials confirmed that the autopsy found no signs of trauma that would have contributed to the actress’s death.
Authorities also said the preliminary investigation had uncovered no evidence of foul play or suspicious circumstances.
However, the results have not yet established Panettiere’s official cause or manner of death.
Further laboratory studies, including toxicology testing, must be completed before the coroner can make a final determination.
The Greenville County Coroner’s Office has said toxicology reports typically take between eight and 12 weeks to complete, although the results could arrive sooner or later.
This means it is not yet known what caused Panettiere to go into cardiac arrest.
While a possible overdose was mentioned in the initial emergency dispatch audio, officials have not confirmed that an overdose occurred or contributed to her death.
The investigation remains active and ongoing, with Panettiere’s official cause and manner of death remaining pending until all outstanding test results have been received.