Hayden Panettiere's younger brother died unexpectedly when he was very young, allegedly hurting the actress-singer.

Friends are concerned that the "Nashville" star would relapse into booze and drugs in order to cope with her immense loss.

According to a source close to the 33-year-old blonde bombshell, she is "inconsolable."

"Jansen wasn't just her brother. He was her confidant and best friend. They had both been burned by Hollywood and shared the experiences with each other," they revealed to Radar Online.

Jansen Panettiere, who starred in his sister's 2011 film "The Forger," was discovered dead in his Nyack, New York residence on February 19.

While the medical examiner did not reveal an official cause of death for the 28-year-old artist-turned-actor, who also suffered from melancholy and anxiety, the Panettiere family as a whole said he died as a result of an enlarged heart.

The 33-year-old actress also discussed her fight to overcome postpartum depression after the birth of her daughter Kaya in 2014, and how she eventually gave up custody while she fought a life-threatening opiate and alcohol addiction.

Friends of the "Bring It On" actress are frightened that she may destroy all of the hard work she has put into her sobriety.

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Hayden only recently revealed her secret addiction.

Hayden Panettiere confessed in an interview with People magazine that she was on a downhill spiral throughout her acting career and succumbed to drugs and alcohol.

"I was on top of the world, and I wrecked everything; I thought I'd struck rock bottom, but suddenly that trap door opens."

She went through trauma counseling and inpatient treatment to help her rehabilitate, and she even made a comeback in "Scream 6," playing her character from the horror franchise.

Hayden admitted that the road to sobriety was not easy, but she doesn't regret even the most heinous things that occurred to her.

"I feel incredibly accomplished and I feel like I have a second chance."

The "Heroes" actress confesses to using "happy pills" when she was just 15 years old.

Her addiction, however, progressed to booze and painkillers.

She sought care right away, which was fortunate because physicians warned her that her liver might fail.

A family statement released earlier this week revealed the true cause of death for Hayden Panettiere's younger brother.

In a statement, they said, "Though it offers little solace, the Medical Examiner reported Jansen's sudden passing was due to cardiomegaly (enlarged heart), coupled with aortic valve complications."

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