Saoirse Kennedy Hill, granddaughter of Robert F. Kennedy, dies at 22; no sign of trauma

The exact circumstances of the death remain unclear.

Saoirse Kennedy Hill, the granddaughter of the late Robert F. Kennedy, died after being found unresponsive Thursday afternoon at the Kennedy Compound, officials said.

An autopsy performed Friday revealed "no trauma inconsistent with lifesaving measures" on Hill's body, the Cape and Islands District Attorney Michael O'Keefe said in a statement. The cause and manner of death are pending the toxicology report, O'Keefe said.

The Kennedy family confirmed the death in a statement.

"Our hearts are shattered by the loss of our beloved Saoirse. Her life was filled with hope, promise and love. She cared deeply about friends and family, especially her mother Courtney, her father Paul, her stepmother Stephanie, and her grandmother Ethel, who said, 'The world is a little less beautiful today,'" the Kennedy family said in the statement.

"She lit up our lives with her love, her peals of laughter and her generous spirit. Saoirse was passionately moved by the causes of human rights and women’s empowerment and found great joy in volunteer work, working alongside indigenous communities to build schools in Mexico. We will love her and miss her forever," the statement continued.

Hill, 22, was the daughter of Paul Hill and Courtney Kennedy Hill, the fifth of 11 children of Robert and Ethel Kennedy.

Further details about the death are unknown at this time.

Barnstable police were called to the Kennedy Compound in Hyannis Port, Massachusetts, on Thursday around 3 p.m. for a report of an "unattended death," O'Keefe said.

"The matter remains under investigation by Barnstable Police and State Police detectives assigned to the District Attorney's Office," the DA's statement read.

Hill was public about her struggles with depression. In 2016, while still a high school senior at Deerfield Academy, she wrote an op-ed for the school's newspaper mentioning that she left school during her junior year for "treatment for my depression and returned to the valley for my senior year."

"I didn’t care that students thought that I had left because of an eating disorder, or that I had been bullied, but it concerned me that my teachers and advisors didn’t know what I had been going through," Hill wrote. "Even though it was helpful for me to discuss my struggles with all of those important people in my life, it was still uncomfortable, and it was hard for me to take the initiative."

Hill went to Boston College, where she was a member of the College Democrats. She was part of the class of 2020 and was studying communication at the university's Morrissey College of Arts and Sciences, Boston College spokesman Jack Dunn said in a statement.

Dunn described Hill as a "gifted student" with many friends on campus, while faculty who taught her described her as "thoughtful and compassionate, and possessing a deep empathy for others."

"We extend our deepest condolences to her family in the wake of this tragic loss," Dunn said.

Hill's grandmother, Ethel, who is 91, was married to Bobby Kennedy from 1950 until he was murdered in June 1968 while running for president. He served as attorney general under his brother, John F. Kennedy, and was a senator from New York when he was assassinated.

The Kennedy compound consists of 6 acres of land along the Nantucket Sound and has been in the family for decades, according to the National Park Service. Both Robert F. Kennedy and John F. Kennedy had homes there.

ABC News' Henderson Hewes and Aaron Katersky contributed to this report.