8-10-12 (London, GB)  --  Alise Post of St. Cloud crashed during her third run in the Olympic B-M-X semifinals today (Fri) in London and failed to qualify for the finals.  Mariana Pajon of Colombia won the gold medal while bikers from New Zealand the Netherlands took silver and bronze.  Post was the eighth seed out of the 16 B-M-X racers going into today's semifinals.