On 25 July 1969, 56 years ago, Senator Edward "Ted" Kennedy pleaded guilty to fleeing the scene of an accident where a young aide died. But as a BBC reporter learnt, Kennedy left many questions unanswered.

"There are people here who plainly feel that ugly and dishonourable things have happened here this summer," said BBC reporter Brian Saxton in August 1969. He was standing outside the courthouse in Edgartown, Massachusetts that would hold the inquest into what was already becoming known as the "Chappaquiddick incident". A month earlier, US Senator Edward "Ted" Kennedy had appeared in the same courthouse to plead guilty to fleeing the scene of a car accident. His young female passenger, Mary Jo Kopechne, had been killed.

The two had been at a party in a rented cottage on Chappaquiddick Island, a popular holiday destination for the US's rich and famous that was only accessible by ferry from Martha's Vineyard. "That last fatal ride on 18 July has already produced a good deal of conflicting stories," reported Saxton. "Stories that have been used by many American journalists to Senator Kennedy's political disadvantage."

At the time, Teddy was the sole surviving son of the influential Kennedy political dynasty. The family had suffered a succession of tragedies in the preceding years. Teddy's older brother, US President John F Kennedy, had been assassinated in Dallas in 1963. The eldest of the four Kennedy boys, Joe Jr, had been killed undertaking a covert wartime mission in 1944, and his sister Kathleen had died in a plane crash over France in 1948. Another sister, Rosemary, was lobotomised at the age of 23 when their father Joseph became concerned about her behaviour. She would end up spending most of her life in an institution. A little over a year before the Chappaquiddick incident, Teddy's remaining brother, Senator Robert F Kennedy, had been shot dead while campaigning in Los Angeles for the Democratic presidential nomination.

In fact, the get-together on 18 July was a reunion for people who had worked on his late brother's ill-fated political campaign. Among the guests present were a group of six female political strategists known as "Boiler Room Girls" because of the hot, windowless office where they worked in Washington, DC. One of these women was the 28-year-old Kopechne, who had worked on the wording of Bobby's speech announcing his presidential candidacy. There was a growing belief that Ted would take up his brother's political mantle. The January before the RFK campaign reunion, he had been chosen by the Democratic party as its youngest ever senate majority whip. He was now widely tipped to be the party's candidate to challenge US President Richard Nixon. There were promising signs that, once again, a Kennedy would sit in the White House.

The Chappaquiddick party was still in full swing when, sometime after 11pm, Senator Kennedy and Kopechne decided to leave. According to the statement he later gave to the police, Kennedy offered to drive Kopechne to the ferry landing, so that she could catch the last ferry back to Edgartown, where her hotel was. However, she did not tell her friends that she was leaving, and she left her handbag and room key behind at the party. It was on the drive to the ferry that the accident occurred.

"The senator said he took a wrong turning on a dark night and was lost, although it's known he was familiar with the island," said Saxton. As Kennedy drove down the unlit Dyke Road, his car veered off a narrow, wooden bridge which had no railings, and plunged into a cold tidal pond. The car landed upside down, and immediately began filling up with water.

"I remember thinking as the cold water rushed in around my head that I was for certain drowning," Kennedy would later say in a television address on 25 July 1969. "Then water entered my lungs, and I actually felt the sensation of drowning."

Kennedy managed to get himself free from the vehicle and swim to the surface. He told police that he called Kopechne's name and,........

© BBC