Context: Loosely based on the 1967 folk song by Bobbie Gentry, and set in the year 1953 in rural Mississippi, the film explores the budding relationship between 19-year-old Billy Joe McAllister (Robby Benson) and 16-year-old Bobbie Lee Hartley (Glynnis O'Connor) (who corresponds with the unnamed narrator of the original song), despite resistance from Hartley's family, who contend she is too young to date. Yet every day, after being dropped off by her school bus at the Tallahatchie Bridge over the Tallahatchie River which leads to the Hartley farm, Bobbie Lee slips away to a local sawmill where Billy Joe works just to hang out with him at the end of his shift.When Bobbie Lee and her father have a confrontation with three thugs driving a battered pick-up truck from a neighboring county across the state line in Alabama, they chase them to the Tallahatchie where they force their truck off the road which ends up dangling off the bridge. With Bobbie Lee's father unwilling to abandon his truck and abandon the precious eggs and cargo he is delivering to the local market, Bobbie Lee is forced to run several miles to the sawmill to ask Billy Joe, her brother and another employee to rescue her father and save his truck. This incident seem to bring Bobbie Lee and Billy Joe more close to each other.One night at a jamboree, Billy Joe gets drunk and seems nauseated and confused when entering a makeshift whorehouse behind the gathering. Later, Bobbie Lee finds out through the town grapevine that Billy Joe was accused of assaulting one of the prostitutes and is wanted for questioning.After disappearing for days, Billy Joe returns to bid an enigmatic goodbye to Bobbie Lee on the Tallahatchie Bridge. When she presents him with her childhood rag doll, he knocks it away from her and it falls into the river while the passing priest, Brother Taylor, sees from afar. After Billy Joe runs off, Bobbie Lee asks if everything is all right and Billy Joe then blurts out: "It ain't all right! I have been with a man... which is a sin against nature, a sin against God!" It is here where he confides in her that on the evening during the jamboree, in his inebriated state, he had sex with another man. Bobbie Lee is somewhat shaken but takes the news very calmly. Overcome with guilt over his homosexual encounter, Billy Joe subsequently kills himself by jumping off the Tallahatchie bridge the next day (off-camera).In the film's final scene, set a few days later after Billy Joe's funeral, Bobbie Lee meets Dewey Barksdale (James Best), Billy Joe's sawmill boss on the bridge as she is leaving town for a while, and he guiltily confesses to her that he was the man whom had sexual relations with Billy Joe that night. She tells Dewey, who is on his way to her house to confess to her father, that the town already falsely suspects that she is carrying Billy Joe's baby and that it would do no good for Dewey to confess now since he could go to prison for sodomy charges. Agreeing with the girl's logic, Dewey offers Bobbie Lee a ride to the bus station, which she courteously accepts.The rest of the story (and song) is history: "A year has come and gone since we heard the news about Billy Joe. Brother married Becky Thompson and they bought a store in Tupelo. There was a virus goin' around, Papa caught it and he died last spring. And now Mama doesn't wanna do much of anything. And me, I spend a lot of time picking flowers up on Choctaw Ridge and dropping 'em into the muddy waters off the Tallahatchie Bridge." 
 Question: How does Billy Joe kill himself?
Output: jumping off the tallahatchie bridge