What Killed Brittany Murphy? Inside Her Untimely Death 15 Years Later — From Shocking Doctor's Notes to Conspiracy Theories and More

Fans were left reeling when the news broke in December 2009 that effervescent actress Brittany Murphy had tragically died in her Los Angeles home at just 32 years old.

"She was a brilliant talent," said an insider, "and then just like that, she was gone."

Devastation quickly turned to confusion as strange details surrounding her passing came to light. While a coroner ruled the death accidental, many suspected foul play.

Added the insider: "It continues to be one of the most shrouded mysteries in Hollywood."

Eleven years later, the star's passing is still raising questions.

According to the official report, the Uptown Girls star died of pneumonia with secondary factors of iron-deficiency anemia and multiple drug intoxication. But now, a new documentary has sparked renewed interest about what really happened to the actress, who died two hours after collapsing on the bathroom floor of the house she shared with her British screenwriter husband, Simon Monjack, and her mother, Sharon Murphy, on the morning of December 20.

In a bizarre twist, Simon passed away just five months later of acute pneumonia and severe anemia.

"The situations were eerily similar," said the insider, adding, "The documentary definitely has people talking again."

In Brittany Murphy: An ID Mystery, forensic pathologist Dr. Cyril Wecht, who was hired by Brittany's estranged father, Angelo Bertolotti, before he passed away in 2019 to investigate his daughter's death, said he is still "perplexed" by the case.

"How could [Brittany] have developed such an advanced state of pneumonia and such an incredible state of iron deficiency?" he asked. "Where in the world was her mother, her husband? Why didn't she receive proper medical care? I was just puzzled by all of it. She had the financial means to see a doctor. And then she had prescriptions for strong opiates."

New theories have emerged. In the ten days leading up to her death, Brittany had been complaining of severe abdominal pain. An investigation by the Los Angeles County Coroner revealed she had picked up a bug called Staphylococcus aureus during a visit to Puerto Rico six weeks before she died.

While Simon and Sharon had also caught it and exhibited symptoms, Brittany seemed fine — at first. But then she developed pneumonia, and her health quickly deteriorated. The coroner said it hit her extra hard because of her anemia, which resulted from heavy, painful periods that ultimately may have killed her. The periods made Brittany more vulnerable to infection, while the drugs she was taking — including Prozac, Klonopin and acetaminophen, as well as Vicoprofen for pain relief — could've caused adverse physiological effects.

"Though the drugs were legal and not considered the primary cause of death," explained the insider, "the elevated levels of the medications cannot be discounted, especially considering her weakened state."

Heartbreakingly, it seems her death could have been prevented.

"She had been sick at least two weeks," the assistant coroner told The Hollywood Reporter. "Had they taken her to a doctor or hospital, it would have been treatable."

There was no shortage of conspiracy theories surrounding Brittany's sad demise — including claims that drug abuse, murder and poisoning were to blame.

"There was talk Brittany had an eating disorder because she lost a drastic amount of weight in the early 2000s," said the insider. "Many assumed she had a raging cocaine habit, though Brittany herself strenuously denied it and claimed she'd never touched the drug."

Her mother, Sharon, was convinced Brittany, and later, Simon, had died from exposure to toxic mold in their Mediterranean-style home, which had previously belonged to Britney Spears.

"They both died of a flu-like illness and Sharon raised h---, saying the builders of the home were responsible and that her lawyers pushed her to accept a settlement for the construction problems," the insider said.

Sharon turned around and sued the lawyers for malpractice, and they later settled out of court for an undisclosed sum. Angelo, who had left Sharon when Brittany was two, believed foul play was involved.

"I have a feeling that there was definitely a murder situation here," he said in 2013.

Angelo sued the Los Angeles County Department of Medical Examiner-Coroner for its findings and requested they hand over samples of Brittany's hair for independent testing, believing that his daughter may have been poisoned.

"But he couldn't get any evidence to hold up, and he didn't do himself any favors by failing to attend two court hearings," dished the insider.

In the end, the suit was dismissed. Tension between Sharon and Angelo made a bad situation worse.

"Brittany's parents didn't get along and this cut fresh wounds," said the insider, adding that many people in Brittany's circle believed Sharon knew more about what happened to her daughter and son-in-law than she was willing to admit. "People still point the finger at her and say it's time she tells the truth and reveals all of her secrets."

Sharon sold Brittany's house in 2011 for $2.7 million and dropped out of sight two years later, and the insider said Brittany's pals find her disappearance "shady."

While no one truly thought she had anything to do with Brittany or Simon's deaths, "it does seem strange that she hasn't been seen or heard from in seven years," noted the insider, adding that Sharon had been omnipresent in Brittany's life.

"Now, Sharon's not speaking anymore, and no one knows why," added the insider. "She refuses to answer questions pertaining to Brittany's death, and that just makes people wonder."