A granddaughter of the late Robert F. Kennedy died of an apparent drug overdose Thursday at the Kennedy compound in Hyannis Port, Massachusetts, adding to a long list of tragedies to strike the Kennedy family.

The death of 22-year-old Saoirse Kennedy Hill comes half a century after her grandfather was gunned down in Los Angeles in 1968, and just as suddenly.

“The world is a little less beautiful today,” her grandmother and Robert F. Kennedy’s widow, Ethel, said in a statement late Thursday confirming the death.

An investigation is underway into the cause of death, but two sources close to the family cited by The New York Times said it was an apparent overdose.

Emergency responders were called to the residence, where Hill's 91-year-old grandmother lives, around 2:30 p.m. on Thursday afternoon. Hill was taken to Cape Cod Hospital in Hyannis, where she was pronounced dead.

While Hill was a virtually unknown member of the famous political family, she was said to have been devoted to human rights and rallied against gun violence in 2018, when she reportedly urged fellow demonstrators to “build a current” and told them they were a “tidal wave” for change.

Hill was a communications major at Boston College and was a member of the class of 2020. The New York Times reports that she chronicled her struggles with mental illness in high school for the student newspaper at Deerfield Academy in Massachusetts.

“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. “Although I was mostly a happy child, I suffered bouts of deep sadness that felt like a heavy boulder on my chest.”

Hill was the daughter of Courtney Kennedy Hill and Paul Michael Hill—one of the Guildford Four, a group of three Northern Irish men and an Englishwoman who were falsely convicted for Irish Republican Army bombings of two English pubs in 1974. Paul Hill was sentenced to life in prison and served 15 years behind bars before his conviction was overturned. Paul and Kennedy Hill married after his release in 1993, and separated in 2006. Saoirse was their only child.

“Our hearts are shattered by the loss of our beloved Saoirse,” the Kennedy family said in a statement. “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.”

Hill’s death is the latest in a series of tragedies to rock the Kennedy family, who lived through the assassinations of President John F. Kennedy in 1963 and Sen. Robert F. Kennedy five years later. Their brother Joseph P. Kennedy Jr. died while serving in World War II, and their sister Kathleen Cavendish died in a plane crash in 1948. John F. Kennedy Jr., JFK's son, also died in a plane crash in 1999, along with his wife and sister-in-law. The string of calamities prompted Ted Kennedy to question in 1969 whether a “curse” was plaguing the family.