Jacqueline Kennedy Onassis had a recurring dream in which her son, John F. Kennedy Jr., would die in a plane crash, claims a new book, "The Day John Died" by Christopher Andersen (a former PEOPLE writer). The book, which is being published today, traces events leading up to the fatal July 16, 1999, air tragedy that claimed the life of John Jr., his wife Carolyn Bessette Kennedy and her sister, Lauren Bessette. Andersen writes that in her last years, "Jackie had a recurring premonition that John would be killed piloting his own plane. She pleaded with Maurice (Templesman, her longtime companion) to do whatever it took to keep John from becoming a pilot." The Kennedy-friendly book also goes on to say that on the night of the air crash, an American Airlines jet altered course to avoid colliding with Kennedy's Piper Saratoga. Furthermore, John and Carolyn, suffering from having been under the media spotlight at the outset of their marriage, had ironed out their difficulties -- at one point she kicked him out of their Manhattan loft -- and were on their way to begin a family.