Great Britain's Liam Phillips has been forced to withdraw from the quarter-finals of the BMX competition at the Rio Olympics after a heavy fall.
Olympian Chris Hoy tweeted that the fall had led to concussion.
Among those offering commiserations are his sister Charley.
The rider from Burnham-on-Sea was knocked off his bike just after the first corner on the track in Rio.
After staying down for a number of minutes Phillips did finally get up from the side of the track but was unable to compete in his second heat and is therefore out of the competition.