President Joe Biden fell on stage at the Air Force Academy Thursday afternoon, sparking looks of concern from onlookers there for the school’s annual graduation ceremony.

Biden arrived at the academy, north of Colorado Springs, to make a commencement address for graduating cadets. On stage, the president praised the diversity of the academy and heralded the next generation of Air Force and Space Force officers.

But during the end of the ceremony, the 80-year-old Biden turned to walk across the stage and tripped.

An Air Force officer and two members of the U.S. Secret Service helped the president to his feet while onlookers – including members of the official delegation on stage – looked over in concern before Biden returned to his seat.

The White House communications director, Ben LaBolt, tweeted out soon after that the president was fine and there was a sandbag on stage while Biden shook hands.

During his 30-minute speech, Biden had warned cadets of the challenges they will soon face and the responsibility that they now must bear. Presidents and vice presidents routinely give cadets the commencement speech, usually in a rotating schedule with the Secretary of Defense, Secretary of the Air Force and Chairman of the Joint Chiefs of Staff.

Biden twice before delivered commencement remarks at the academy when he served as vice president under former President Barack Obama.

The Associated Press contributed to this report.

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