Huge BMX pile-up in men's semi-final race

Last updated at 15:26
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Watch the BMX pile up...

A group of BMX riders ended up in a massive pile-up in one of the men's quarter finals at the London Olympics on Thursday.

All but one of the riders crashed on the first bends on the course leaving New Zealand's Marc Willers as the only rider left.

He carried on and won the race whilst some of the men managed to get back on their bikes and carry on riding.

Check out the video above to see how it happened.