Boston, Aug. 3 -- A granddaughter of Robert F. Kennedy, who was assassinated in 1968 while running for president, has died. Saoirse Kennedy Hill was 22.

The Kennedy family confirmed the death in a statement Thursday night after police responded to a call about a possible drug overdose at the storied Kennedy compound in Hyannis Port, Massachusetts. The statement was issued by Brian Wright O'Connor, a spokesman for Saoirse Hill's uncle, former congressman Joseph P. Kennedy II.

Hill was the daughter of Robert and Ethel Kennedy's fifth child, Courtney, and Paul Michael Hill, who was one of four people falsely convicted in the 1974 Irish Republican Army bombings of two pubs. The two are now divorced.

"She lit up our lives with her love, her...