Heartbreaking reason Carolyn Bessette's sister Lauren was also on JFK Jr's plane when he crashed and killed them all in 1999... and all the other revelations from MAUREEN CALLAHAN's new book

An explosive new book by DailyMail.com columnist Maureen Callahan poses a bombshell new theory about John F. Kennedy Jr's 1999 plane crash that killed him and his wife Carolyn Bessette.