Hayden Panettiere's 911 Call Reveals Desperate Struggle to Save Actress' Life After 'Drug' Overdose

Zach Hickerson's desperate plea to save Hayden Panettiere was heard in fresh audio from his 911 call, RadarOnline.com has learned.

Panettiere died on August 16 at a residence in Greenville, South Carolina. Her partner's brother, Zach, made a call to police when he found her, sounding scrambled and concerned. When first responders arrived at the residence, where Zach and Brian Hickerson were waiting, she was already dead.

"Oh God, oh my God!" Zach could be heard saying on the audio. He told the dispatcher, "I walked in after church to my brother and his girlfriend's apartment and she's unconscious."

He reported to the operator that Panettiere was not breathing. While they worked on getting responders to the location, he was instructed to find a defibrillator if there was one available in the apartment complex.

Without one, they instructed Zach and Bryan to try CPR, "flat on her back and remove anything from under her head," on Panettiere in an effort to save her life. Panicked, the brothers continued to ask for instructions before one said, "Oh my god! I know how to do this! How many times!"

The emergency responders arrived, taking over their attempt. The 911 call was ended, and Panettiere's revival was unsuccessful. She was pronounced dead at the scene.

While Narcan was found nearby, there was no indication on the that it was administered. However, Zach claimed Brian administered Narcan, which is a medication that reverses opioid overdoses.

The Greenville County Coroner's Office in South Carolina ruled Panettiere's death "accidental" after a toxicology reporter. According to the report, her cause of death was ruled as the toxic effects of fentanyl, 4-ANPP, Alprazolam, Methocarbamol, and Quetiapine.

Coroner Mike Ellis ruled her death an accident after "no signs of trauma were discovered" in the autopsy "that would have contributed to the death."

Police opened an investigation into her death. They suspected she was given the drugs from her "long-term drug dealer."

Before her death Panettiere was using drugs again after spending years clean.

"There are a slew of messages about drugs," a source told TMZ, claiming incriminating electronic messages from Panettiere and her dealer, in which they were "very specific about purchasing black-market pills," were uncovered throughout the course of the investigation.

Brian told authorities Panettiere had a "bag of medication" with her when she died.

The source indicated Panettiere took one pill before her death, but it was heavily laced with fentanyl, which is 50 times stronger than heroin.

No one has been charged in connection with the death of Panettiere, yet.

Lesley Vogel, Panettiere's mother, pushed blame onto a "toxic individual" in her daughter's life. Notably, Panettiere was not speaking with her before the incident.

“Although my daughter and I were estranged, it was not for lack of care or love,” Vogel said. “It was due to the involvement of a toxic individual who I believe led to her death.”

She later identified Brian directly. "This person in her life that we have been trying to get rid of for quite some time was with her at her death, and that was Brian Hickerson," she said.

Brian, who was seen speaking with police during the investigation, was not charged with any wrongdoing. He reportedly was asleep in the residence in a separate room when Zach found Panettiere.