DAREDEVIL NIK WALLENDA'S UNPRECEDENTED NIAGARA FALLS TIGHTROPE WALK TO AIR LIVE ON ABC, FRIDAY, JUNE 15

"Countdown to Niagara: The Greatest Megastunts of All Time" Airs 8:00-9:00 p.m., ET

"Megastunts: Highwire Over Niagara Falls - Live!" Airs 9:00-11:00 p.m., ET

On June 15, Nik Wallenda will walk approximately 1,550 feet on a tightrope wire, suspended 173 feet above the raging waters of Niagara Falls -- an unprecedented feat that has been banned for over 125 years. ABC will air Wallenda's long-planned stunt live. The "Megastunts" ABC special will be part of a two-part, three-hour event that will include an hour devoted to the greatest stunts in history and culminate in Wallenda's walk. Anchored by Josh Elliott and ESPN's Hannah Storm, and featuring reporting from Elliott, Storm, Bill Weir and Sam Champion, "Countdown to Niagara: The Greatest Megastunts of All Time" (8:00-9:00 p.m., ET) and "Megastunts: Highwire Over Niagara Falls - Live!" (9:00-11:00 p.m., ET) air FRIDAY, JUNE 15 on the ABC Television Network.

Wallenda's tightrope walk over Horseshoe Falls, the biggest of the three falls that make up Niagara Falls, is unprecedented and will be a culmination of a life's work for Wallenda, 33, and his entire daredevil family. "It's very exciting. This is something I've wanted to do for a long time," says Wallenda, a seventh-generation member of the legendary Great Wallendas, a travelling family circus troupe dating back to 1780. "It's been a dream I've had since I was six years old when I first visited the falls with my parents. I remember looking across... and thinking, it would be cool to be the first person in the world to do this."

Crossing the Niagara River on a tightrope has been banned since 1890. Thirteen tightrope artists have traversed the gorge throughout history, notably the Great Blondin, but Wallenda discovered in his research that no tightrope artist had ever before walked directly over the awesome and raging cascades.

VIDEO:

Top Stunts Countdown: Sneak Preview - Nik Wallenda's great-grandfather did headstands over gorge http://abcnews.go.com/2020/video/top-stunts-countdown-sneak-preview-16549069

Watch Nik Wallenda practice for his high-wire walk across Niagara, Fri., 8 p.m. http://abcnews.go.com/2020/video/daredevil-trains-niagara-falls-stunt-16545552

PHOTOS: The World's Greatest Stunts http://abcnews.go.com/Entertainment/slideshow/photos-worlds-greatest-stunts-16499679

STORY: Walk Across Niagara: By the Numbers http://abcnews.go.com/Entertainment/nik-wallendas-walk-niagara-numbers/story?id=16528783

BLOGS: Vote: What's Your Favorite Stunt? http://abcnews.go.com/blogs/entertainment/2012/06/vote-whats-your-favorite-stunt/

Before the Niagara Walk: Nik Wallenda's Biggest Challenge http://abcnews.go.com/blogs/entertainment/2012/06/before-the-niagara-walk-nik-wallendas-biggest-challenge/

John Green and Ethan Nelson are the co-executive producers and Morgan Zalkin is the senior producer.