Complex sentence: With the decline of Dixieland jazz circa 1963, Billy Crystal turned 15 and that would be the age when his father lost his business, and died that year at the age of 54 after suffering a heart attack while bowling.
Split into simpler sentences: With the decline of Dixieland jazz circa 1963, Billy Crystal turned 15. That would be the age when his father lost his business, and died later that year at the age of 54 after suffering a heart attack while bowling.