Veteran jockey Carlos Marquez Jr. was injured when his mount in the fourth race Friday at Hawthorne, Dancing Nora, broke down in midstretch. Marquez was pitched hard to the dirt track but was not struck by any trailing horses, though jockey Javier Diego was unseated avoiding the fallen horse with his mount, Momma Joanna. Diego took off the rest of his Friday mounts but did not require immediate medical treatment, and Momma Joanna, but Dancing Nora suffered catastrophic injuries, and Marquez was transported to Loyola Medical Center.

At 8:30 Friday evening, Marquez's agent, Penny Ffitch-Heyes, said Marquez had a full range of motion in his limbs, was alert, and had not injured his brain. The extent and exact nature of his injuries was not fully known, and Marquez still was being evaluated.