An American man has become the first person to successfully cross from the US to Canada over Niagara Falls on a tightrope, in a daring display of acrobatics broadcast live around the world.
Nik Wallenda, 33, a member of the famed "Flying Wallendas" family of aerialists, walked the half-kilometre, 5 centimetre-width cable stretched across the falls live on American television.
Along the way, suspended over the falls, Wallenda took small, steady steps on a slick cable through swirling winds, the ABC reports.
"Oh my gosh it's an unbelievable view," he said as he crossed over the falls.
"This is truly breathtaking."
American television presenters occasionally interviewed him along the walk, asking him about conditions and how he was coping.
"That mist was thick and it was hard to see at times," he said later in the walk, when he was asked about the greatest challenge.
"Wind going one way, mist another. It was very uncomfortable for a while."
Soon after arriving in Canada, Wallenda called his grandmother on a mobile phone.
"Hey Oma, I love you," he said. He said he had promised to call her up as soon as he completed the feat because she could not be there.
The TV network insisted he wear a safety harness connecting him to the cable - a first for the performer - and warned it would stop broadcasting if he unhooks it.
TV ordered tether
TV producers, maintained that a problem with the tether would spell the end of the stunt.
"If there is a safety issue, if the tether gets snagged, then Nik would simply sit down on the wire. Untethered, we will not be broadcasting a live image of him," said Jeffrey Schneider, senior vice president at ABC News.
If the harnessed Wallenda fell, ABC said it would switch its cameras to a wider angle and begin covering the entertainment event as a news story, Schneider said.
More than a century ago, an aerialist known as the Great Blondin walked a high wire strung farther down the gorge, but a trek over the brink of the falls has never been attempted.
Since the Great Blondin took his high-wire walk, a ban has been in place on similar stunts over the famed falls. Wallenda waged a two-year crusade to convince U.S. and Canadian officials to let him try the feat.
A private helicopter rescue team is part of the $US1.3 million that Wallenda said he has spent on the walk.
Wallenda's great grandfather Karl Wallenda died in 1978 during a walk between two buildings in Puerto Rico at age 73. Wallenda repeated that walk last year with his mother.
Wallenda said he has obtained permits for a future walk over the Grand Canyon in Arizona, which would be roughly three times longer than the walk over Niagara Falls.