Andy Soule, a U.S. Army veteran, lost both his legs to a bomb in Afghanistan in 2005. Four years ago, he won America's first medal — Olympic or Paralympic — in the biathlon event. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR

Former Marine Josh Sweeney lost both of his legs to a bomb in Afghanistan in 2009. He's competing with the U.S. Men's Sled Hockey team at the Paralympics in Sochi. David Gilkey/NPR hide caption

itoggle caption David Gilkey/NPR