PHOTOS | US Runner's Olympic Heartbreak

Morgan Uceny, middle, competes in the women's 1500m final during the 2012 London Olympic Games at Olympic Stadium. (Photo: John David Mercer-USA TODAY Sports)

Morgan Uceny reacts after falling to the ground during the 1500m finals during the London 2012 Olympic Games at Olympic Stadium. (photo: James Lang-USA TODAY Sports)

Morgan Uceny reacts after falling to the ground during the 1500m finals during the London 2012 Olympic Games at Olympic Stadium. (Photo: James Lang-USA TODAY Sports)

Morgan Uceny reacts after falling to the ground during the 1500m finals during the London 2012 Olympic Games at Olympic Stadium. Mandatory Credit: James Lang-USA TODAY Sports

Morgan Uceny (USA) reacts to falling during the women's 1500m final during the London 2012 Olympic Games at Olympic Stadium. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Gamze Bulut (TUR), right, leads the field as Morgan Uceny (USA) falls down in the women's 1500m final during the 2012 London Olympic Games at Olympic Stadium. (Photo: John David Mercer-USA TODAY Sports)

Hellen Onsando Obiri (KEN), left, and Abeba Aregawi (ETH), in green, leap to avoid Morgan Uceny (USA), bottom, in the women's 1500m final during the 2012 London Olympic Games at Olympic Stadium. (photo: John David Mercer-USA TODAY Sports)

Morgan Uceny falls to the ground during the 1500m finals during the London 2012 Olympic Games at Olympic Stadium. (photo: James Lang-USA TODAY Sports)

Morgan Uceny (USA) tries to avoid the feet of other runners after falling in the women's 1500m final during the 2012 London Olympic Games at Olympic Stadium. (photo: John David Mercer-USA TODAY Sports)

Morgan Uceny (USA) reacts to falling during the women's 1500m final during the London 2012 Olympic Games at Olympic Stadium. (Photo: Robert Deutsch-USA TODAY Sports)