More than a month after Hayden Panettiere was found unresponsive inside a South Carolina residence, officials have released the findings that answer one of the biggest questions surrounding the actress’s sudden death.

The Greenville County Coroner’s Office announced on September 22 that Panettiere died from the toxic effects of fentanyl, 4-ANPP, alprazolam, methocarbamol and quetiapine. Her death was ruled an accident.

The determination brings new clarity to a case that had remained under investigation since the 36-year-old actress died on August 16.

Panettiere, widely known for her work in Heroes, Remember the Titans and other film and television projects, had been temporarily staying at a residence in Greenville when the emergency unfolded.

At approximately 1:51 p.m. that afternoon, authorities received a 911 call reporting a cardiac arrest at 701 Easley Bridge Road.

Emergency personnel arrived and found Panettiere in cardiac arrest. Advanced life-saving measures were attempted, but responders were unable to revive her.

She was pronounced dead at 2:32 p.m.

Investigators Found No Trauma

The circumstances surrounding Panettiere’s death immediately prompted an investigation involving both the Greenville County Coroner’s Office and Greenville City Police Department.

According to officials, she was found unresponsive inside the home where she had been staying.

An autopsy was later conducted by a board-certified forensic pathologist.

Investigators did not find injuries or signs of trauma that contributed to her death, a detail that helped narrow the focus of the medical examination toward toxicology and other testing.

Her body was released to her family on August 18 and transferred to a mortuary that evening.

At that stage, however, the precise medical cause remained unresolved.

The answer would come several weeks later, when the coroner’s office disclosed the combination of substances involved and officially classified the death as accidental.

Among the substances listed were fentanyl, 4-ANPP, alprazolam, methocarbamol and quetiapine.

The ruling marks the most significant official development in the case since Panettiere’s death.

Brian Hickerson Was at the Residence

Panettiere was not alone when the emergency occurred.

Her on-again, off-again boyfriend, Brian Hickerson, was at the residence, along with his brother, Zach Hickerson.

A police report later revealed additional details about what officers encountered at the scene.

Brian showed investigators a bag containing medications Panettiere had been taking.

The report also described the emotional reactions of the two brothers. Zach was characterized as highly emotional, while Brian did not appear visibly emotional until Panettiere was officially pronounced dead.

Those details attracted attention in the weeks after her death as authorities continued working to understand the circumstances surrounding her final hours.

Brian later issued a statement through his attorney, Sloan Ellis, saying the case was still under investigation and emphasizing that police had reported no signs of foul play.

He declined to comment further out of respect for Panettiere’s family and the ongoing inquiry.

With the release of the coroner’s findings, authorities have now provided an official medical explanation for her death while maintaining the determination that it was accidental.

A Career That Began Early

Panettiere had spent much of her life in the public eye.

She began acting at a young age and eventually became one of the most recognizable television stars of her generation.

Her performances in projects such as Remember the Titans and Heroes brought her widespread recognition, and she later built another major television following through Nashville.

Her father remembered her after her death as a powerful presence, describing his daughter as an extraordinary light with a strong and unmistakable personality.

Yet behind the success and celebrity, Panettiere had also spoken openly about difficult periods in her personal life.

She had discussed struggles with alcohol and substance use, as well as postpartum depression, and had sought treatment at different stages.

Those experiences became an increasingly important part of the way she spoke publicly about her life.

The Painful Decision Involving Her Daughter

Panettiere is survived by her daughter, Kaya, whom she welcomed in 2014 with former fiancé Wladimir Klitschko.

For the first several years of Kaya’s life, Panettiere and Klitschko raised their daughter together.

In 2018, however, Panettiere made what she later described as an extremely difficult decision: Klitschko received full custody while she sought help for alcohol use, substance abuse and postpartum depression.

That chapter remained deeply emotional for her.

In May 2026, only months before her death, Panettiere discussed the custody decision publicly and pushed back against the idea that she had simply abandoned or “given away” her daughter.

She said the suggestion was deeply painful and did not reflect what had actually happened.

Panettiere explained that seeking treatment had been her own decision, rather than something others had forced upon her.

The comments offered a glimpse into how strongly she continued to feel about the way that period of her life had been interpreted publicly.

For her, treatment and the custody arrangement were connected to a difficult attempt to address serious personal struggles, not a lack of love for her child.

A Death That Prompted Weeks of Questions

From the moment Panettiere’s death was announced, the circumstances surrounding it raised questions.

She was only 36.

She had been staying temporarily in South Carolina.

She was found unresponsive inside a residence, and people close to her were present when the emergency occurred.

Police quickly said there were no signs suggesting foul play, but the absence of an immediate cause of death left a period of uncertainty.

The autopsy answered part of the question by finding no contributing trauma.

The toxicology results have now provided the remaining medical explanation.

The combination of fentanyl, 4-ANPP, alprazolam, methocarbamol and quetiapine was determined to have caused the fatal toxic effects, and officials classified the manner of death as accidental.

The ruling closes a major unanswered chapter in the investigation into how Panettiere died, even as the emotional impact of her loss remains for those who knew and loved her.

Remembered Beyond Her Final Hours

The official findings inevitably place attention on the circumstances of Panettiere’s death, but they represent only one part of a life that unfolded publicly for decades.

She was an actress whose career began in childhood, a mother, a daughter and a woman who had increasingly chosen to speak candidly about addiction, treatment and mental health.

Her final years included both professional appearances and deeply personal conversations about struggles she had once kept more private.

That openness gave audiences a more complicated picture of someone who had experienced extraordinary success while also confronting serious difficulties away from the screen.

Now, with the coroner’s September 22 announcement, one of the most important unanswered questions following her August 16 death has been resolved.

Hayden Panettiere’s death was caused by the toxic effects of multiple substances and has officially been ruled accidental.

For her family, friends and those who followed her career, the determination offers an answer to how she died — while leaving behind the much larger memory of the life, work and relationships that came before her final day.