Newly released 911 recordings reveal the frantic moments after 17-year-old Austin Metcalf was fatally stabbed during a high school track meet in Texas. The calls capture the desperate efforts of friends, coaches, and first responders as they raced to save the teenager's life. The recordings were among hundreds of exhibits made public by a Collin County court following the murder trial of Karmelo Anthony, who was convicted in Metcalf's death and sentenced to 35 years in prison.