From ABC: Daredevil Nik Wallenda's death-defying Niagara Falls tightrope walk to air as a primetime special

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, from the U.S. to Canada -- an unprecedented feat that has been banned for more than 125 years.

Wallenda, 33, announced the much-anticipated official date for his historic walk in a news conference at Niagara Falls last week. on Friday's "Good Morning America," it was revealed that ABC has the exclusive worldwide broadcast rights, which were secured by Lincoln Square Productions, for Wallenda's long-planned stunt to air 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 of all time and culminate in Wallenda's walk. "Megastunts: The Greatest Stunts ... Ever" (8 p.m.) and "Megastunts: Man on Wire: Live from Niagara" (9 to 11 p.m.) 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 him and his entire daredevil family.

"It's very exciting. This is something I've wanted to do for a long time," said 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 6 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. Wallenda, who holds six Guinness World Records -- including the longest bicycle ride on a tightrope without a safety net and the largest human pyramid on a high wire -- set his sights on the unprecedented feat.

In November 2011, Wallenda approached officials in the U.S. and Canada with a proposal to cross directly over Horseshoe Falls, from Goat Island on the U.S. side to Table Rock on the Canadian side. Park Commissions in New York and Ontario, Canada, were extremely skeptical about permitting a high-wire stunt like this, citing worries about the cost, copycats, security, not to mention Wallenda's safety, and initially rejected the idea. But Wallenda was determined and made it his mission to secure the permissions to achieve this life-long dream.

"I am very challenge-driven person," he said. "Don't tell me, 'It can't be done,' because I'll find a way to do it."

After months of work and a time-consuming negotiation, the Ontario Parks Commission approved a one-time exemption in February to allow Wallenda to attempt a single crossing, reversing the 128-year ban on stunts. The Niagara Parks Commission has specified that such feats can only be attempted once every two decades.

"My great grandfather taught us to never give up. This is just the ultimate story of just never giving up," Wallenda said, adding that the legal battle was the biggest challenge of his career. "I got two laws changed that were over a hundred years old ... now, guess what... Nik Wallenda is going to walk across the falls June 15, live on ABC."

To prepare for his greatest stunt yet, Wallenda will train on land using a wire identical to the one he will walk on over on the falls this summer. In training, he will be sprayed with heavy mist from a fire hose to simulate the falls' raging waters, and be put up against a wind machine, generating gusts up to 60 miles per hour. Tourists and fans will be able to visit him in training at the Seneca Niagara Casino & Hotel.

In many ways, Wallenda has been practicing for this moment for his entire life. The Florida native began walking the wire at age 2 and learned the ropes from his father, Terry Troffer, a retired acrobat who serves as his chief rigging engineer and safety expert. During the June 15 stunt, Wallenda will be able to talk with his father through an earpiece the entire time.

Though he admits his family is "a little nervous" about this walk, Wallenda said they are proud and happy that he will get to tackle a life-long dream.

With the televised June 15 walk, Wallenda is carrying out the legacy of his great grandfather, family patriarch Karl Wallenda, who fell to his death at age 73 in 1978 on a tightrope walk in San Juan, Puerto Rico. But Wallenda, who has already taken on and conquered the same walk that claimed Karl's life, is not worried that he will meet the same fate as his grandfather.

"We can tell immediately about why he lost his life. His biggest challenge was his age and his physical ability. The wire was also not put up properly ... whereas I'll be rehearsing and knowing exactly what I'll experience," Wallenda said.

The walk itself is expected to take approximately 30 to 40 minutes and is expected to draw thousands of spectators on the U.S. and Canadian sides, and boost tourism to the region leading up to and long after the historic event.

Wallenda is focused and remarkably at ease, considering the tremendous risk involved. It's just between him, the wire and -- now -- the breath-taking beauty of Niagara Falls.

"It's peaceful actually.

I get in the zone," he said. "It becomes relaxing."