In BMX Racing, Danger Is Never Far From the Lead

Connor Fields of the U.S. was hospitalized after crashing in the semifinals.

TOKYO — Perhaps it was an ominous sign, or maybe just a normal one, when BMX racing at the Olympics began Monday with a training run collision between a top cyclist and a marshal who wandered onto the track. When the competition began on Thursday, a Japanese rider flipped over her handlebars in the first heat, ending her Olympic experience in less than a minute and sending her away with a broken collarbone. Friday, the day the medals were doled out, began with a thunderous downpour, which felt right, because BMX is high in drama. Water slicked the course, merely adding to the danger factor. Reasonable minds delayed the start and sent workers onto the paved serpentine course of rollers and high-banked turns with brooms and dryers.