Zac Vawter stands on "The Ledge" after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk chats with his mother Judy Kirk, after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Ryder Kopacz 3 looks at his father's medal after Tate Kopacz finished Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Michelle Howard after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter gets interviewed after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter gets interviewed after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter gets interviewed after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter stands on "The Ledge" after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter walks up the stairs at Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

A climber takes a break on the 34 1/2 floor during Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter walks up the stairs at Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter walks towards the stairs for Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk, after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk chats with his mother Judy Kirk, after finishing Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Zac Vawter rests before Skyrise Chicago, the world's tallest stair climb at the Willis Tower. He has the World's first Neutral-Controlled Bionic Leg. Sunday, November 4, 2012. I Brian Jackson~Sun-Times

Senator Mark Kirk emerges at the finish of Skyrise Chicago, the world's tallest stair climb at the Willis Tower. Sunday, November 4, 2012. I Brian Jackson~Sun-Times