Santa Anita horse deaths cast shadow over racing industry

Santa Anita Park is one of the country’s most famous and storied horse racing venues, and this weekend it was due to host a major prep contest for May’s Kentucky Derby. But a spike in deaths among horses training there -- 21 have died since December 26 -- has prompted the track to close for testing, amid rising alarm from critics who fear the sport is too grueling to begin with. John Yang reports.