Shocking twist in death of Kennedy heiress as RFK Jr drops new details about what caused her overdose

By WILL POTTER, US SENIOR NEWS REPORTER Published: 19:48, 7 August 2026 | Updated: 19:59, 7 August 2026 Robert F Kennedy Jr. revealed that his niece's tragic death in 2019 was caused by a fentanyl overdose as he paid tribute to her on the anniversary of her passing.  The Health and Human Services (HHS) Secretary shared a touching tribute to his late niece Saoirse Kennedy Hill on Friday - but revealed never-before-reported details of how she passed away in 2019 aged 22.  As he mis-spelled her name as 'Saorsie', Kennedy wrote: 'Remembering my beloved niece Saorsie Kennedy Hill, a luminous soul who died 7 years ago this week of an accidental fentanyl overdose.' The post featured several photographs of Saoirse from her childhood, including beaming family photos and lavish yachting vacations.  Kennedy promptly deleted the Instagram post soon after sharing it to his millions of followers, however it is unclear if he was aware of revealing her cause of death.  The Daily Mail has contacted the HHS for comment.  At the time of Saoirse's passing in August 2019, toxicology reports found methadone, fluoxetine, norfluoxetine, diazepam, nordiazepam and alcohol in her system. Fluoxetine is an anti-depressant, and diazepam is medication to treat alcohol withdrawal symptoms and alcohol withdrawals.  Robert F Kennedy Jr. revealed that his niece Saoirse Kennedy Hill's tragic death in 2019 was caused by a fentanyl overdose, as he paid tribute to her on the anniversary of her passing Kennedy mis-spelled his niece's name as 'Saorsie' in the since-deleted post  Kennedy shared a touching tribute to his late niece, writing on Friday that she was 'a luminous soul who died 7 years ago this week of an accidental fentanyl overdose' Saoirse - the granddaughter of assassinated presidential candidate Robert F Kennedy and daughter of Courtney Kennedy Hill - was found unresponsive at the Kennedy family compound in Hyannis Port, Massachusetts on the night of August 2, 2019.  Aged just 22, the heir to the Kennedy dynasty was at home with many of her family members including grandmother Ethel Kennedy when she overdosed.  She was raced to Cape Cod Hospital, and she was pronounced dead soon after.  Ethel Kennedy, then-91, shared a heartbreaking statement following Saoirse's death, saying that 'the world is a little less beautiful today.' Saoirse had been open about her struggles with mental illness, depression and anxiety, including sharing an op-ed in her student newspaper at the prestigious Deerfield Academy in 2016.  She wrote at the time that her depression 'took root in the beginning of my middle school years and will be with me for the rest of my life.' The political scion indicated that the weight of her family name wore on her, as she said she suffered from 'deep bouts of sadness that felt like a heavy boulder on my chest.'  Kennedy family members at Saoirse Kennedy Hill's funeral on August 5, 2019 in Massachusetts