Slash’s stepdaughter Lucy-Bleu Knight left suicide notes before tragically taking her life in a rental unit, the Los Angeles Medical Examiner confirmed to The Post on Monday.

The Guns N’ Roses guitarist’s 25-year-old stepchild passed away on July 19 of hydrogen sulfide toxicity. Her manner of death was ruled a suicide.

The coroner just released an official report on her passing, revealing she left notes to her loved ones and had “a history of undiagnosed mental illness.” The examiner also stated that her family said “she was paranoid and would have hallucinations.”

“This 25 year old female was found in a residence with suicide notes and evidence of hydrogen sulfide inhalation,” the report read, disclosing her toxicology results tested positive for the presence of thiosulfate.

According to the report, Knight was found on the bathroom floor of her Airbnb. She was scheduled to stay in the unit for four days after checking in on July 15. The property manager attempted to contact her several times.

When they didn’t hear from Knight, the manager checked on her but was “unable to access the front door, which seemed to have resistance when she attempted to open it.”

The property manager contacted emergency services for a welfare check.

What happened next is grim. The Post has chosen not to include all the details out of respect for the family’s privacy.

When police arrived on the scene, “they also noticed resistance they described as ‘suction’ when opening the front door of the unit. Upon opening the locked door, Officers observed a hand-written sign apparently meant for first responders warning about toxic gas. A chemical scent was also detected by Officers, who immediately backed out of the residence and called for assistance.”

The L.A. Fire Department Squad 87 Hazmat Unit and Engine 287 were next on the scene. They discovered that Slash’s stepdaughter had used a cooler to mix a lethal dose of chemicals, including cerium hydroxide, sulfuric acid, hydrochloric acid, and sodium thiosulfate.

Knight had also used plastic bags and tape to seal light fixtures, electrical outlets, ceiling vents, and cracks in the bathroom window and floors.

The report noted that Knight had pills in her wallet, including escitalopram, which helps maintain mental balance, and paliperidone, used to treat the symptoms of mental disorders.

“A packet of suicide notes was found on a side table in the main room. According to family, she had no previous suicide attempts but did have prior ideations,” the report read.

It also stated that Knight had been hospitalized for 5150 holds twice in 2024.

“The doctors were attempting to diagnose the decedent, but no official diagnosis was available. Family stated that she was paranoid and would have hallucinations.”

Slash revealed his stepdaughter’s passing in a heartfelt tribute.

“Lucy-Bleu Knight (December 6, 1998), beloved daughter of Meegan Hodges and Mark Knight, stepdaughter of Samantha Somers Knight and Slash, sister of Scarlet Knight, stepsister of London and Cash Hudson, passed away peacefully in Los Angeles, California, on July 19, 2024,” the legendary guitarist wrote in part.

He called her “an incredibly talented artist, a passionate dreamer, and a charming, lovable, sweet soul” and asked for the family’s privacy.

Knight was the daughter of Slash’s longtime partner, Meegan Hodges, and her ex, Mark Knight. The rocker first dated Hodges in 1989. They rekindled their relationship in 2015.

Slash shares two children — sons London, 21, and Cash, 20 — with his ex-wife, Perla Ferrar. The musician and Ferrar were married from 2001 to 2018.