By BETH HARRIS
AP Racing Writer
The 3-year-old colt whose Kentucky Derby victory in May came under scrutiny because of a positive drug test has collapsed and died after a workout at Santa Anita in Southern California. Trainer Bob Baffert says Medina Spirit suffered a heart attack. The colt had just completed five furlongs in his second workout since finishing second in the Breeders’ Cup Classic a month ago at Del Mar. The colt will undergo a full necropsy to try to determine the exact cause of death.