FILE - In this Oct. 30, 2013 file photo, an exercise rider takes a horse for a workout at Santa Anita Park with palm trees and the San Gabriel Mountains as a backdrop in Arcadia, Calif. A person with direct knowledge of the situation says a 21st horse has died at Santa Anita. The person spoke to The Associated Press on the condition of anonymity Tuesday, March 5, 2019, because the fatality has not been announced publicly. A total of 21 horses have died since the race track's winter meet began on Dec. 26. (AP Photo/Jae C. Hong, File)