Beware the ides of July: Anniversaries of the fatal crashes involving Ted Kennedy and nephew John F Kennedy Jr on Martha's Vineyard

• The Kennedy family is remembering two tragic anniversaries this week involving two of he political dynasty's most prominent men
• Tuesday marked the 20th anniversary of the fatal plane crash that killed John F Kennedy Jr, his wife Carolyn and his sister-n-law Lauren in the Atlantic Ocean
• On Thursday, it will be the 50th anniversary of the death of  Mary Jo Kopechne, who died in a car crash while travelling with Ted Kennedy in Chappaquiddick
• Kennedy escaped from the submerged vehicle and said he made several futile attempts to rescue Kopechne, who was trapped inside
• He said his failure to report the incident to police for 10 hours was 'indefensible'

The Kennedy family is remembering two tragic anniversaries this week involving two of he political dynasty's most prominent men.

Tuesday marked the 20th anniversary of the fatal plane crash that killed John F Kennedy Jr, his wife Carolyn and his sister-n-law Lauren just off the coast of Martha's Vineyard.   

Two days later, on Thursday, it will be the 50th anniversary of the death of  28-year-old Mary Jo Kopechne, who lost her life in a car crash while travelling with Ted Kennedy, who escaped unscathed that night and fled the scene.

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That too happened on Martha's Vineyard.  Ted had gone Martha's Vineyard to race in the Edgartown Regatta and on the evening of July 18, 1969, attended a party at a rented house on Chappaquiddick Island. 

Guests included Kennedy friends and several women, including Kopechne, who had worked on the presidential campaign of his brother Robert F. Kennedy, assassinated a year earlier.

Kennedy and Kopechne, 28, left the party together and a short time later their car plunged into Poucha Pond. Kennedy escaped from the submerged vehicle and said he made several futile attempts to rescue Kopechne, who was trapped inside.

The career politician, who died in 2009, later described his failure to report the incident to police for 10 hours as 'indefensible.'

At the time of the crash, Kennedy was the Majority Whip in the Senate, seven years after he won a special election in Massachusetts for the seat vacated by his brother John when he was elected president. 

He had presidential ambitions, but Richard Nixon decided to use the crash to kill any chance of Kennedy challenging him in the next election.  

Nixon was also considering going after the victim, with one file at the time stating that she likely died after performing an 'immoral act.' 

That memo, from administration member Jack Caufield, went on to state that since Kennedy fled the scene a priest was not able to read the victim her last rites.

'The extreme importance ... needs no explanation here,' reads the memo, hointing that the victim's afterlife might have been impacted by her and Kennedy's actions that night.

Nixon's aggressive line was no surprise to those who were familiar with his tactics explains Whalen.

'Nixon’s reputation for being a pretty tough counter puncher, now if you’re going to challenge him for the presidency, everything is on the table here, including what happened in Chappaquiddick,' Whalen points out.

Nixon was able to kill Kennedy's plan of a possible run, but not derail his future in the Congress.

Kennedy would hold his seat until his death in 2009, and did once attempt a run for president against incumbent Jimmy Carter in 1980, a race he lost.

Carter then subsequently lost to Ronald Reagan in the general election

Kennedy had been the frontrunner due to Carter's abysmal approval rating at the time, which at one point dipped below 20 percent.

That lead began to narrow however when the Chappaquiddick scandal was revisited and Kennedy failed to adequately address the tragedy. 

John Jr lost his life while travelling to the wedding of his cousin Rory.

He had almost been alone that night after Carolyn threatened to skip the nuptials.

Carolyn had a change of heart at the last second however, and the two set off with her sister Lauren on July 16, 1999.

John had taken off from Essex County Airport in Fairfield, New Jersey, at 8.39pm that night, bound for the airfield in Martha's Vineyard.

He never made it to his final destination.

The air traffic controller at the island airport alerted the regional FAA office in Connecticut just after 10pm when the plane had failed to arrive.

In the end, it was the conditions that evening most likely caused the tragedy which took three lives.

Three days later, parts of the plane were detected on the ocean floor.

On July 21, five days after the plane went missing, the three bodies were found and removed from the underwater wreckage.

The ashes of John, 38, his wife Carolyn, 33, and his sister-in-law Lauren, 34, were scattered at sea on July 22 just off of Martha's Vineyard by friends and family.

John Jr. made the decision prior to his death to have his ashes be scattered at sea rather than be buried alongside his father, mother, sister Arabella and brother Patrick at Arlington National Cemetery.