BOSTON - APRIL 20 : Fans cheer on marines marching the marathon in full 40 lb packs during the Boston Marathon April 20, 2009 in Boston. About 25,000 runners took part in the 113th edition.
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BOSTON - APRIL 20 : Fans cheer on marines marching the marathon in full 40 lb packs during the Boston Marathon April 20, 2009 in Boston. About 25,000 runners took part in the 113th edition.