The Cape & Islands district attorney's office said Hill died after being taken to Cape Cod Hospital.
Authorities said afterward in a statement: "An autopsy performed today has revealed no trauma inconsistent with lifesaving measures".
Hill was the only daughter of Paul and Courtney Kennedy Hill, the fifth child of RFK and Ethel, and is the latest member of the family to succumb to the so-called "Kennedy curse".
"Her smile and laughter lit up every room she entered with every occasion turning into a spontaneous dance party", she added. "When Saoirse's heart is happy/All the world seems bright and gay/And when Saoirse's eyes are smiling/Sure, they steal your heart away".
(David L Ryan/The Boston Globe via AP) The casket of Saoirse Kennedy Hill enters Our Lady of Victory Church in Centerville, Mass., on August 5, 2019.
Toilet explodes in Florida home after lightning strikes septic tank
A woman reported the unusual incident in which her toilet actually exploded into hundreds of pieces. A Port Charlotte resident's toilet exploded after lightning struck their home's septic tank.
Romelu Lukaku increasingly likely to join Inter Milan from Manchester United
The striker trained with Belgian side Anderlecht on Monday and Tuesday as he continues to seek a move away from Old Trafford. Reports emerged earlier today that the Belgian has been handed a hefty fine by United for failing to report for training.
New Trailer 'Pokemon Sword and Shield' Reveals Team Yell Punks
These fans, Team Yell, harass other trainers in the region in an effort to make sure Marnie comes out on top. Pokemon Sword and Shield is set to debut as a Nintendo Switch exclusive on November 15.
Saoirse was the coed of Boston College, she was a human rights fanatic, alongside together with her research she was keen on politics.
Edward Kennedy, John and Robert's brother, once even talked about whether there was a "curse" hanging over the family.
"Saoirse was fierce, both in her love for her family and yearning for justice", he wrote. "His life was full of hope, promise, and love". After the funeral, several of the Kennedys were seen returning by boat to the family's compound in Hyannis Port, Massachusetts. "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 attractive today, '" the Kennedy family said in the statement.
Another of Ms Hill's uncles, Michael Kennedy, died on New Year's Eve in 1997 in a skiing accident in Colorado at the age of 39. Although I was mostly a happy child, I suffered bouts of deep sadness that felt like a heavy boulder on my chest.
Our thoughts go out to Saoirse's family and friends at this time. "A fearless adventurer, she inspired curiosity and daring in her friends".
Mariah Kennedy Cuomo, cousin to the deceased and daughter of New York Gov. Andrew Cuomo, wrote in a tribute that she would love Saoirse "now and always".
"But her greatest gift was to find humor in everything and to give us all the gift of her laughter-and our own". On Friday, he described his niece's death as "a wound too large to ever heal".