Another major meet, another tumble to the track for American runner Morgan Uceny.
Uceny was tripped from behind on the last lap in the Olympic 1,500-meter final Friday night, landing hard on her right knee and hip. She smacked her palms against the surface before erupting into tears.
She was in a position to challenge for a medal, but her performance will go down as ''DNF'' - did not finish. Uceny was helped into the medical area after the race and then left the stadium without speaking to reporters.
Last year at the world championships, Uceny, of Mammoth Lakes, Calif., entered the race as one of the top runners. But she fell before winding up a disappointing 10th.