A pair of jockeys suffered serious injuries when they were thrown from their respective horses during the second race at Churchill Downs on Thursday, according to a report in the Louisville Courier Journal.

The Kentucky Derby, the first leg of horse racing’s triple crown, will take place Saturday during the 12th of 14 races schedule at Churchill.

On Thursday, the jockeys who were both hospitalized after they went flying onto the dirt track as they approached the far turn during a 1 1/16-mile maiden, 10-horse claim race. Jockeys Irving Moncada and Emmanuel Giles both needed to be taken to a nearby hospital via ambulance following the incident.

Moncada, who was mounted on Territoriality, was found unconscious, according to his agent, Joe Paulley. However, he regained consciousness approximately two hours later and eventually released from the hospital later Thursday.

Giles, meanwhile, was also taken to a hospital for observation and his agent, Nancy Bahena, said he suffered injuries to his spine and shoulders before undergoing X-rays and further testing.

It’s unknown what caused the jockeys to fall. However, jockey Martin Chuan, who was riding Valerie Blue, was disqualified from the race, apparently for playing a role in the spill.