PHOENIX, Mar 20: Aerialist Nik Wallenda plans to cross the Grand Canyon in June on a tightrope 1,500 feet in the air, without a safety harness – a feat that will be televised live. Wallenda said he would traverse a remote section of crimson-hued canyon owned by the Navajo Nation in what will be his first major stunt since he last year became the only person to walk a wire over the brink of Niagara Falls. (agencies)