ARCADIA, Calif. - A maiden filly broke both front legs at the conclusion of a half-mile workout Thursday morning on the main track at Santa Anita, according to her owner and trainer, David Bernstein. She was euthanized, becoming the 22nd equine fatality at Santa Anita since the winter meet began on Dec. 26. Princess Lili B, a 3-year-old filly, broke down at the finish line at 8 a.m. on a fast track. “We’re devastated,” said Tim Ritvo, chief operating officer of track owner The Stronach Group.  Ritvo said training would continue Thursday morning at Santa Anita, which reopened its main track for workouts early this week.