Authorities have determined that Saoirse Kennedy Hill, the 22-year-old granddaughter of assassinated presidential candidate Robert F. Kennedy, died of an accidental drug overdose.
The Chief Medical Examiner's office concluded in its report that her cause of death was "acute methadone and ethanol toxicity in combination with other prescription medications," Michael O’Keefe, district attorney for the Cape and Islands, said in a statement.
The manner of death was accidental, the report said.
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A toxicology test found methadone, fluoxetine, norfluoxetine, diazepam, nordiazepam and alcohol in her system. Hill's death certificate was made public Friday.
Fluoxetine is an antidepressant, and diazepam is used to treat anxiety and alcohol withdrawal symptoms.
Hill was found unresponsive at a home at the storied Kennedy compound in Hyannis Port, Massachusetts, on Aug. 1. She was later pronounced dead at Cape Cod Hospital.
She was scheduled to start her senior year at Boston College this fall. The college said in a statement earlier this year that she was a communications major and "a gifted student."
Hill was the daughter of Robert and Ethel Kennedy's fifth child, Courtney, and Paul Michael Hill, who was one of four falsely convicted in the 1974 Irish Republican Army bombings of two pubs.
"She lit up our lives with her love, her peals of laughter and her generous spirit," the family said in a statement issued after her death, adding that she was passionate about human rights and women's empowerment and worked with indigenous communities to build schools in Mexico.
"The world is a little less beautiful today," the statement quoted Hill's 91-year-old grandmother, Ethel Kennedy, as saying.
Hill had written frankly and publicly about her struggles with mental health and a suicide attempt while in high school. "My depression took root in the beginning of my middle school years and will be with me for the rest of my life," she wrote in a February 2016 column in The Deerfield Scroll, the student newspaper at Deerfield Academy, the elite private school in western Massachusetts she attended.
Hill wrote that she became depressed two weeks before her high school junior year started and she "totally lost it after someone I knew and loved broke serious sexual boundaries with me." She wrote that she pretended it hadn't happened, and when it became too much, "I attempted to take my own life."
She urged the school to be more open about mental illness.
Robert F. Kennedy was gunned down in Los Angeles in 1968 after winning California's Democratic presidential primary. He had served as attorney general in the administration of his brother, President John F. Kennedy, who was assassinated in Dallas in 1963. He also served as a U.S. senator from New York.
RFK's family, like the rest of the Kennedy dynasty, has been touched by tragedy.
One of his and Ethel Kennedy's 11 children, Michael Kennedy, was killed in a skiing accident in Aspen, Colorado, on New Year's Eve 1997 at age 39. And in 1984, another son, David Anthony Kennedy, died of a drug overdose in Florida at age 28.
JFK's son, John F. Kennedy Jr., was killed with his wife and sister-in-law when his small plane crashed off Martha's Vineyard, Massachusetts, in July 1999.