Gymnast Shawn Johnson ends comeback, retires

DES MOINES, IOWA -- Shawn Johnson is calling it a career, ending her attempts at making a second Olympic team because of a lingering knee injury.

The Olympic gold medalist and 2007 world champion announced her retirement Sunday, June 3rd, four days before the start of the U.S. gymnastics championships. Johnson says her left knee, injured in a January2010 ski accident, continued to slow her down, and she worried about the long-term damage if she kept competing.

The 20-year-old from West Des Moines, Iowa, was one of the biggest stars at the Beijing Olympics. Along with her gold on balance beam, she won silvers in the all-around, team competition and floor exercise.

At the 2007 world championships, Johnson won the all-around, led the Americans to their third team title and took gold on floor.