Amputee with nerve-controlled bionic leg makes historic climb in Chicago skyscraper

31-year-old amputee Zac Vawter made medical history Sunday, climbing 103 stories of the Willis Tower with a state-of-the-art bionic leg controlled by electrical impulses from the muscles in his upper leg, including a rewired hamstring. He finished the climb in 45 minutes. More at the Chicago Trib, and CNN.