Hayden Panettiere was found unresponsive inside a South Carolina rental on Sunday, with new reports revealing that her on-again, off-again boyfriend Brian Hickerson and his brother were both at the residence.

Panettiere, 36, had traveled from Los Angeles to South Carolina with Brian the day before her death. The actress, best known for Heroes and Nashville, was staying in the Greenville area when the medical emergency happened.

According to TMZ, Brian’s brother, Zach Hickerson, was the person who discovered Panettiere unresponsive. Sources told the outlet that she was sitting in a chair in the living room when Zach found her. Brian was reportedly asleep in another room at the time.

The discovery led to a desperate attempt to save the actress.

What Happened to Hayden Panettiere?

Emergency crews were called to the residence at about 1:50 p.m. on Sunday, Aug. 16. Panettiere was in cardiac arrest when first responders arrived.

Paramedics performed advanced life-support measures, including CPR, but they were unable to revive her. Panettiere was pronounced dead at 2:32 p.m.

Early reports have raised the possibility of an overdose. Dispatch information referenced both cardiac arrest and a possible overdose, and Narcan was reportedly found at the residence. Narcan, also known as naloxone, is an emergency medication used to reverse an opioid overdose.

However, officials have not determined that an overdose killed Panettiere.

An autopsy found no signs of trauma that contributed to her death, and authorities have said there were no signs of foul play. Her official cause and manner of death remain undetermined while investigators wait for toxicology results, which the Greenville County Coroner’s Office said could take several weeks.

Brian Hickerson Was at the Residence

Brian’s presence has drawn attention because of his long and troubled history with Panettiere.

According to a police report, Brian and Zach were both at the residence during the emergency. Zach was described as emotional while emergency workers tried to save Panettiere.

Brian reportedly became visibly emotional after Panettiere was pronounced dead. He also showed police a bag containing medication she had been taking, although details about the medications were redacted from the report.

Panettiere and Brian began dating in 2018, and their relationship became the subject of intense public attention.

Brian previously faced domestic violence charges involving Panettiere. Their relationship went through several difficult periods, including separations, but the two later reconnected. Recent reports indicate they were romantically involved again before her death.

TMZ reported that the couple had kept their renewed romance largely private. A source told the outlet that Panettiere had been advised to distance herself publicly from Brian while promoting her memoir, even though they were still together privately.

Panettiere’s Mother Speaks Out About Brian

Panettiere’s estranged mother, Lesley Vogel, strongly criticized Brian following her daughter’s death.

Vogel told NBC News that Brian was someone the family had been trying to remove from Panettiere’s life for a long time. She specifically pointed to the fact that he was with her around the time she died.

Her comments came as questions continued to surround the actress’s final hours.

There has been no finding that Brian caused Panettiere’s death, and authorities have reported no evidence of foul play. The investigation into exactly what killed her remains open.

Questions Remain About Her Death

Panettiere had previously spoken publicly about her struggles with alcohol and addiction, including in her memoir, This Is Me: A Reckoning. She also discussed the pressures she faced after becoming an actress at a very young age.

For now, exactly how Panettiere died remains unanswered.

What is known is that she was found unresponsive, went into cardiac arrest and could not be revived. Reports have pointed to a possible overdose, and Narcan was found at the scene, but those details do not prove what caused her death.

The final answer is expected to depend heavily on toxicology testing.

Until those results are complete, Panettiere’s official cause of death remains undetermined.