After starting the day with a realistic chance of winning three medals, Britain were relying on Fox-Pitt to hold off the challenge of the United States, who are only four points adrift, in the showjumping phase today to clinch a bronze.
The gold already appears to be heading to France as Nicolas Touzaint managed to avoid adding any penalties to the 29.40 that put him in front after the dressage phase.
The French have also established a clear lead in the team competition and although Britain have a chance of equalling their secondplaced finish in Sydney four years ago, the loss of Fox-Pitt makes it harder for them to close the sixpoint gap behind Germany. Mary King now becomes part of the scoring-British team - as the top three riders only count towards the team event. GB team leader Will Connell said: "Of course the whole team are extremely upset for William, Tamarillo and the owners of the horse.
"William had an outstanding result when riding at Badminton this year and this is a very unfortunate way to end his Olympic campaign. I am sure we will see William and Tamarillo returning to the world stage - but this is a setback."