American Connor Fields was carried off the Tokyo 2020 BMX course on a stretcher and taken to a waiting ambulance after a shocking crash in the men's semi-finals.
The 2016 Rio Olympics gold medallist went down before the first bend amid a tightly bunched pack of riders, two of whom hit the deck with him – Dutchman Twan van Gendt and France's Sylvain Andre..
Van Gendt said of the incident: "I landed the jump and there was two guys crashing in front of me and there was nowhere to go, that's it.
"I've been racing with those guys all my life, almost. It's a tough competition. We race hard, as you see. We're all on the limit and this is what can happen. I'm happy I'm quite OK. We'll see what the damage is."
There was no official word of 28-year-old Fields' condition and the injuries he may have sustained.
Gold in the later final went to the Netherlands' Niek Kimmann, with Britain's Kye White taking silver and Colombia's Carlos Alberto Ramirez Yepes coming away with bronze.
Australian Saya Sakakibara suffered a heavy crash in the women's semi-finals and was also carried off, but she was able to give media interviews afterwards.
Sending hugs to Connor Fields and Saya Sakakibara after they crashed out of the cycling BMX racing semi-finals. We're thinking of you!— Olympics (@Olympics) July 30, 2021