French Olympic gymnast Samir Ait Said has suffered a leg break while performing in the vault at Rio 2016.
The 26-year-old's left leg folded beneath him as he landed badly during the men's qualification event on Saturday, before swinging loosely below the knee as he fell to the floor.
Said, who won gold on the rings at the 2013 European Championships, was taken off on a stretcher and acknowledged the crowd as he departed.
French team leader Corrine Moustard-Callon told BBC Sport: "We don't know what happened, except it was his tibia. He is in the hospital with a doctor now. We will do more exams to see if it is just the bone.
"It is very difficult for the team. He was one of the friendliest on the team which is very difficult. He came to win a medal and gave everything."
Said's injury came minutes after Germany's Andreas Toba hurt his knee during floor exercise.