Thoroughbreds provide many reasons to marvel. The fastest can top 40 mph. Their speed-producing features — extraordinary concentration of muscle, body and lungs forming a natural bellows, oversized hearts circulating ten gallons of blood — inspire comparison to locomotives. Yet the 1,100-pound animals, taking 20-foot-plus strides, gallop on ankles which have been likened to glass. Suddenly, the entire sport of thoroughbred racing stands on fragile legs. The Preakness Stakes, the second jewel of horse racing’s Triple Crown, is set for Saturday at Pimlico Race Course in Baltimore. The NBC Sports team of Mike Tirico, Randy Moss and Eddie Olczyk preview the race. (Published Friday, May 17, 2019) The crisis reared up at famed Santa Anita Park in California, where 23 horses broke down and had to be killed during a recent 14-week period. It put a national spotlight on a hard reality the public normally doesn’t think about: Horses commonly break down during racing or training and are put to death. The goal is to end the suffering, but a central Pa. horse vet argues it happens too often. Derby Winner Country House Won’t Run in Preakness In Pennsylvania, 87 horses died at the state’s three thoroughbred racing venues last…