Joe Biden Down - What really happened

Earlier in the day, Biden was caught on video stumbling, and hitting the floor before cadets and Secret Service members rushed to grab his arms while he was handing out diplomas in Colorado.
'I got sandbagged,' he joked to reporters following the tumble, after the White House insisted that he was OK.
But as he got off the plane Thursday evening, the 80-year-old commander-in-chief was again seen bumping his head on the doorframe.