What happened to Ted Kennedy at the Chappaquiddick incident

On the night of July 18, 1969, Kennedy was on Martha's Vineyard's Chappaquiddick Island at a party for the "Boiler Room Girls", a group of young women who had worked on his brother Robert's presidential campaign the year before. Leaving the party, Kennedy was driving a 1967 Oldsmobile Delmont 88 with one of the women, 28-year-old Mary Jo Kopechne, as his passenger, when Kennedy drove off Dike Bridge into the Poucha Pond inlet. Kennedy escaped the overturned vehicle and swam to safety, but Kopechne died in the car. Kennedy left the scene and did not call authorities until after Kopechne's body was discovered the following day.