Mary Jo Kopechne, 28 years old and a respected political operative, was found dead in the overturned car of Sen. Ted Kennedy, D-Mass., in a tidal pond near Chappaquiddick Island on this day in history, July 19, 1969.
Known as the "Chappaquiddick incident," the drowning death of Kopechne and the chain of events before and after the tragedy became a national scandal for the young senator from Massachusetts — and "derailed Ted Kennedy’s presidential ambitions for good," noted the History Channel.
What actually happened that night is unclear, for a multitude of reasons.
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What is known is that Kennedy left a party late on the evening of July 18 with Kopechne, drove his car off Dike Bridge on Chappaquiddick Island, escaped from his car — and returned to his hotel.
He did not report the incident until later in the morning of July 19, after his car (and Kopechne's body) had been discovered.
In a 12-minute long televised speech that the gave on July 25, Kennedy attempted to explain what had happened earlier that week.
Kennedy claimed that he attempted to free Kopechne from the car multiple times before giving up due to exhaustion — and that he did not call the police as he was mildly concussed and in a state of shock.
The senator said the gathering was "a cook-out I had encouraged and help sponsor for a devoted group of [Robert] Kennedy campaign secretaries."
"Mary Jo was one of the most devoted members of the staff of Sen. Robert Kennedy. She worked for him for four years and was broken up over his death," said Ted Kennedy.
"Because she was such a gentle, kind and idealistic person, all of us tried to help her feel that she still had a home with the Kennedy family."
"For this reason, and because she was such a gentle, kind and idealistic person, all of us tried to help her feel that she still had a home with the Kennedy family."
Kennedy denied the "widely circulated suspicions of immoral conduct that have been leveled at my behavior and hers regarding that evening," and said that he was not "driving under the influence of liquor."
Said Kennedy, "I regard as indefensible the fact that I did not report the accident to the police immediately."
In the speech, Kennedy explained that rather than calling the police, he "walked back to the cottage where the party was being held and requested the help of two friends, my cousin, Joseph Gargan and Phil Markham, and directed them to return immediately to the scene with me — this was sometime after midnight — in order to undertake a new effort to dive down and locate Miss Kopechne."
"Their strenuous efforts, undertaken at some risk to their own lives, also proved futile," he said.
Kennedy further acknowledged that there were calls for his resignation from the Senate.
He was first elected to the Senate in a special election in 1962, serving the remainder of his brother's term after John F. Kennedy was elected president.
Ted Kennedy was subsequently reelected to a full six-year term in 1964, according to the Senate website.
"And so I ask you tonight, the people of Massachusetts, to think this through with me. In facing this decision, I seek your advice and opinion," he said.
"In making it, I seek your prayers — for this is a decision that I will have finally to make on my own."
Kennedy did not resign.
He went on to represent the Commonwealth of Massachusetts in the Senate until his death in 2009 at age 77.
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He served no time in jail: He pleaded guilty to leaving scene of an accident and received a suspended two-month jail sentence, multiple sources reported.
No autopsy was performed on Kopechne.
It has been debated that perhaps she might have been rescued had the accident been reported earlier.
In an August 1969 interview with TIME Magazine, Mary Jo Kopechne's parents expressed frustration at how their daughter's death was handled.
"There are two sides here," Mrs. Kopechne told the magazine.
"Mr. Kopechne and I on this side and the Kennedy name on the other. Everybody is on that side."
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And while Mr. and Mrs. Kopechne told the publication they accepted Kennedy's excuse of "shock" as the reason he did not immediately go to the police, they were less accepting of the actions of his friends.
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"I cannot understand Mr. Gargan and Mr. Markham," said Mrs. Kopechne. "They weren't in shock. Why didn't they get help? That's where my questions start."
The 2018 film "Chappaquiddick" earned rave reviews for its retelling of the long-discussed and debated story.
In the film, actor Jason Clarke played Kennedy, while actress Kate Mara played Kopechne.
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"Chappaquiddick reminds us that without the Kennedy name and influence, the man who drove a car off a bridge, swam to shore and left a young woman to die, and then went into hiding and defense mode, should have gone to jail for a long time," said reviewer Richard Roeper of the Chicago Sun-Times.