The death of four horses at Churchill Downs has overshadowed preparations for the Kentucky Derby. Two horses trained by Saffie Joseph Jr. collapsed on the track and died over the past week. Two others also died as either a result of racing or training, including Derby entrant Wild On Ice. Joseph is set to saddle Lord Miles in the first jewel of the Triple Crown on Saturday. But he has said he’s unsure of plans after the two deaths from his barn. Churchill Downs, in a statement, expressed concern over the deaths and said officials would press for answers.