Article continues below advertisementDiane Keaton's death reportedly didn't come as a complete surprise to those closest to her.While the Annie Hall icon's passing on October 11 was officially attributed to pneumonia, a friend claimed the actress had been quietly battling an unknown condition before she died.Article continues below advertisement"She was struggling with an unnamed illness," the pal told an outlet, adding that her death "was not a shock."Article continues below advertisementSource: MEGADiane Keaton reportedly battled an unnamed illness before her death.