President Biden has fallen on stage while handing out diplomas to Air Force Academy cadets in Colorado. The 80-year-old commander-in-chief stumbled and fell to his knees and then got back up during the graduation ceremony in an incident likely to spark more concerns about his age as the nation's oldest president seeks a second term. He was assisted by Air Force officials when he fell to the ground. The president then walked away without help and appeared to point to a sandbag on the stage that he appeared to trip over. 'He's fine,' White House Communications Director Ben LaBolt tweeted...