For the large Kennedy clan already stricken with many tragedies, the circumstances of this latest one are unbelievably cruel.
They were gathering at the family compound at Hyannis Port to celebrate the wedding of Rory, the youngest daughter of the assassinated Robert Kennedy, when the news came. The small aircraft of Mr John F Kennedy jnr, the little "John John" who bravely saluted the coffin of his assassinated father 36 years ago, was missing.
The Kennedy compound where the marriage was to take place now became the scene for a Mass celebrated on the porch of Ethel Kennedy's beach-house where the family offered prayers that the lives of John, his wife, Carolyn, and her sister, Lauren, might have been spared when the single-engined Piper disappeared off nearby Martha's Vineyard. However, hope is fast running out as baggage and debris from the plane have been found.
For the senior member of the family present, Sen Edward Kennedy, it is also the 30th anniversary of another Martha Vineyard's tragedy, Chappaquiddick, which dashed his presidential hopes forever.
Only 17 months ago, Rory, whose wedding has now been postponed, cradled the head of her brother, Michael, as he lay dying after an accident on a ski slope in Aspen.
Americans had probably believed that the Kennedy dynasty, the nearest thing to a "royal family" in the US, had seen its fill of personal tragedies, but now what should have been a joyous occasion for the Kennedys beside the sea they loved has turning to yet another tragedy as they face the prospect of mourning the latest victim of what many now call "the curse of the Kennedys".
The tragedies in the Kennedy family, often involving air crashes, go back to 1944 when Joseph Kennedy jnr, a navy pilot and oldest brother of Jack, Bobby and Teddy, was killed when his aircraft blew up while on a mission to destroy a launch site for German V-2 missiles. His body was never found.
Two priests called to tell the parents, Joe snr and Rose, at Hyannis Port. She recalled later: "There were no tears for Joe and me, not then. We sat a while, holding each other close, and wept inwardly, silently."
Joe told Rose: "We've got to carry on. We must take care of the living. There is a lot of work to be done." Joe also urged the rest of the family to go racing in their boats as they had planned because their dead brother would have wanted that.
Last Saturday, Teddy, the only brother to reach middle age, did go sailing, a traditional Kennedy therapy for grief as well as a love of the sea.
Four years later in 1948, the second Kennedy daughter, Kathleen, called "Kick", was killed when the small aircraft she was flying in with her English fiance crashed in southern France. Her father identified her body when it was brought down from the mountains.
For the religious Rose, the decision of Kathleen in 1944 to marry a Protestant aristocrat from the Cavendish family in a registry office was also a tragedy for a Catholic girl.
He was killed several months later in Normandy.
When Kathleen died she was preparing to marry another Protestant Englishman who was divorced.
Tragedy also struck the eldest Kennedy girl, Rosemary, once renowned for her beauty, who has been institutionalised since 1941 after a failed lobotomy operation ordered by her father to cure what was seen at the time as mental retardation. She is now 80. Jack Kennedy's struggle with Addison's Disease which almost killed him on several occasions had not stopped his rise to the presidency with vital help from his father's fortune and influence, but soon after that triumph in 1963, Joe snr had a massive stroke which paralysed him.
He lingered on for eight years unable to speak as he was told of the assassinations of Jack and Bobby and of the Chappaquiddick accident by Teddy himself.
The Camelot aura of the Kennedy White House was shattered for the presidential couple when their son, Patrick Bouvier Kennedy, who was born six weeks prematurely on August 7th, 1963, died two days later.
Earlier in the marriage a baby girl had been still-born and was not named.
Three months later came the shots at Dallas which cut down the young, vital president and plunged the US and much of the world into mourning. The world also watched the unforgettable pictures of "John John" saluting his father's coffin outside St Matthew's Cathedral in Washington as it passed on its way to Arlington Cemetery.
It was the little boy's third birthday.
An air crash nearly claimed the life of Teddy, the youngest of the Kennedy brothers, when he broke his back in an aircraft accident in June 1964, but he still was elected to the senate later that year to take the Massachusetts seat once held by his brother.
Bobby Kennedy belatedly entered the presidential race in 1968 which was thrown open when Lyndon Johnson announced he would not seek re-election. However, his bid ended in tragedy the very day he won the California primary and was well poised to win the Democratic nomination.
He was shot by a young Arab nationalist in the kitchen of the Los Angeles hotel where he was celebrating his victory.
Now Teddy Kennedy would have to take over the leadership of the growing clan and be a surrogate father for Bobby's family as Ethel struggled to rear her 10 children. She was pregnant with the youngest, Rory, when Bobby was shot.
Now Rory's wedding day has been ruined by yet another Kennedy tragedy.
Just over a year after Bobby's assassination, on July 18th, 1969, Teddy organised a party for six of the women volunteers who had worked in Bobby's campaign. The party was on Chappaquiddick, a tiny island separated from Martha's Vineyard by a narrow channel.
Teddy left the party to catch the last ferry back to his hotel on the bigger island and Mary Jo Kopechne (28) took a lift. He took a wrong turn and drove off a bridge into the water. He escaped from the car but she was found drowned inside the next morning.
Teddy claimed he made numerous attempts to rescue her before going back to the cottage to seek help from some aides. He also said he swam the 200 yards back to the main island but made no attempt to report the accident until 10 hours later, after numerous phone calls to friends and advisers. He was not charged with manslaughter but with leaving the scene of an accident and fined.
Legally he escaped lightly. Politically any hopes of ever becoming president died with Ms Kopechne as his unsuccessful challenge to President Jimmy Carter showed in 1980.
Tragedies of various kinds were also in store for the next generation of Kennedys.
Teddy's son, Edward jnr, had to have his right leg amputated for cancer in 1973.
In the same year, Joe Kennedy, eldest son of Robert, was the driver of an over-loaded jeep which overturned on Nantucket Island and resulted in a young woman being paralysed for life. Joe jnr surprisingly retired from active politics last year after 11 years as a member of Congress.
In 1984, David Kennedy, another son of Robert and Ethel, died of a drug overdose in a hotel near the family holiday home in Palm Beach, Florida.
It was at this house that another Kennedy, William Kennedy Smith, was alleged to have raped a woman in 1991 after visiting a nightclub with his uncle, Ted Kennedy, and Ted's son, Patrick, who is also a member of Congress. William, who is the son of Jean Kennedy-Smith, former US ambassador to Ireland, was acquitted on the rape charge but with the media blanket coverage, it was a severe ordeal for her and the family.
In December 1997, Michael Kennedy, another son of Robert and Ethel, was killed in a skiing accident at Aspen, Colorado. He had earlier been accused of having an affair with the family's teenaged babysitter.
The Kennedy saga is not all tragedy, of course. Teddy will eventually be seen as one of the most effective senators working for liberal causes. His sister, Jean, has won her reputation for helping the Northern Ireland peace process.
Jack Kennedy's brief White House years and Bobby's identification with the under-privileged and with minorities are still seen as inspirational for young people. Most of those of the younger generation of Kennedys who had their youthful problems with drugs successfully overcame them.
Kathleen Kennedy Townsend, eldest daughter of Bobby and Ethel, is making an impressive political career in Maryland where she is lieutenant governor and is tipped to become governor or even a possible running mate for Vice-President Al Gore in next year's election.
However, it is the tragedies which make the news and remind the US that to be a Kennedy can mean sudden death and failure as well as riches, fame and glamour.