Daredevil Nik Wallenda became the first person to walk on a tightrope across the Niagara Falls, taking steady, measured steps Friday night for 1,800 feet across the mist-fogged brink of the roaring falls separating the U.S. and Canada. "I feel like I'm on cloud nine right now," an exuberant Wallenda told reporters after accomplishing what he said was his childhood dream before an estimated 112,000 people crowding the shores of both countries and millions more who watched a live television broadcast.