Neil Sedaka, one of pop's most enduring songwriters, whose career extended from after World War II to the countercultural days of Elton John, died Friday at age 86, his family said. Sedaka was the writer behind hits such as "Breaking Up Is Hard to Do," "Love Will Keep Us Together" and dozens of other hits. His cause of death was not clear. "Our family is devastated by the sudden passing of our beloved husband, father and grandfather, Neil Sedaka," his family said in a statement to NBC News. Sedaka, who was also a performer himself, had three No. 1 hits, nine Top 10 hits, and 30 songs on the Billboard singles chart, according to Billboard. He wrote songs and collaborated with Connie Francis, Frank Sinatra, Elvis Presley, Tom Jones, Elton John and Clay Aiken. Sedaka was born in New York City's Brooklyn borough and grew up in its Brighton Beach section. He was the son of a taxi driver, who was the son of Turkish Jewish immigrants.…