Ledecky smashes own record to win women's 400m freestyle
United States' swimmer Katie Ledecky broke her own world record on Sunday on the way to winning the women's 400 meters freestyle gold medal at the Rio Olympics.
Britain's Jazz Carlin took the silver medal, and Leah Smith of the U.S. won bronze.
Ledecky led from start to finish to set a new mark of three minutes, 56.46 seconds, bettering the 3:58.37 she set in Australia two years ago.
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If she wins all three, Ledecky - who also won a silver in the 4x100 freestyle relay on Saturday - will be the first women to achieve the feat since American Debbie Meyer at the Mexico City Olympics in 1968.
The 2012 London champion Camille Muffat of France was among 10 people killed in March 2015 when two helicopters collided in a remote region of Argentina during the filming of a reality TV show.