The holder of half a dozen world records will walk across the Grand Canyon on a steel cable with nothing but the Little Colorado River 1,500 feet below on June 23. With no tethers or safety nets, the walk will be the highest tightrope attempt ever for the 34-year-old, at a height taller than the Empire State Building. Last year, Wallenda, a seventh-generation member of the “Flying Wallendas” family of acrobats, became the only person to walk a wire over the brink of Niagara Falls. Photo: Nik Wallenda walks across a tightrope 200 feet above U.S. 41 on January 29, 2013 in Sarasota, Florida. (Photo by Tim Boyles)

Nine year old girl Barsati reacts while walking on a tightrope in Mumbai on February 11, 2014. Barsati, and her younger brother Rajababu, (4) earn an average of around 2000 rupees (32 dollars) per day from pedestrians and tourists performing various acts on the tightrope near the city's iconic landmark Gateway of India. (Photo by Indranil Mukherjee/AFP Photo)

Performer Zhang Yashu from a Chinese ballet company perform during a photo shoot in front of the Australia's iconic landmarks Opera House (L) and Habour Bridge in Sydney on February 17, 2014. One of China's celebrated dance campanies is bringing one of the country's biggest ballet production to Australia for a series of performances in Sydney and Melbourne. (Photo by Saeed Khan/AFP Photo)

Bar girls use their mobile phones outside a bar along the Walking Street where bars and sеx scenes are a commonplace July 31, 2016 in Pattaya, Thailand. Thailand's first female minister of tourism would like the sеx trade that is a huge business in the country to be banned. Tourists flock to Thailand for many sights including beautiful beaches but also for sеx tourism. Cities like Bangkok and Pattaya are well known as hubs of the Southeast Asian sеx trade, despite the fact that prostitution has been illegal in Thailand since 1960. (Photo by Paula Bronstein/Getty Images)

Belarusian Sergei Selekh plays with his 6-month-old tamed wolves on the outskirts of the village of Gaina, 45 kilometers (28 miles) north of Belarus capital Minsk, Wednesday, December 31, 2014. Selekh owns a farmstead, where sheep, wolves and an ethnographic museum serve as entertainment for guests. (Photo by Sergei Grits/AP Photo)

Iraqi firefighters try to stop the fire of burning oil wells in Kirkuk, northern Iraq, 02 June 2016. Two Khabbaz oil field wells in Kirkuk Province, northern Iraq, exploded by suspected insurgents, a security official said. (Photo by EPA/Stringer)

Rita Ora performs an intimate gig at the newly relaunched Tezenis store at Oxford Circus crossing to celebrate her recent lingerie collaboration with Tezenis on December 13, 2016 in London, England (Photo by David M. Benett/Dave Benett/Getty Images for Tezenis)

A picture taken on March 9, 2017, shows a boy playing with a cat next to a 1948 Buick parked outside the home of Mohammad Mohiedine Anis in the formerly rebel-held al-Shaar neighbourhood. (Photo by Joseph Eid/AFP Photo)