* Completes walk in about 25 minutes
* Officials ask for his passport (Adds comments from onlookers)
By Neale Gulley
NIAGARA FALLS, N.Y., June 15 (Reuters) - Aerialist Nik Wallenda made a historic tightrope crossing over Niagara Falls on Friday night, stepping onto safe ground in Canada to wild cheers after completing his journey through wind and mist on a 2-inch (5-cm) cable.
Wallenda, a member of the famed "Flying Wallendas" family of aerialists, took a little more than 25 minutes to walk 1,800 feet (550 metres) from the U.S. side in the dark of night over treacherous waters and rocks in a nationally televised event.
Arriving on the Canadian side, he hugged his family and greeted Canadian officials, who playfully requested the 33-year- old American's passport. Asked the purpose of his visit, Wallenda told the officials he had come to "inspire people."
More than 150 years ago, French aerialist Charles Blondin, known as "The Great Blondin," famously walked a high wire strung farther down the Niagara gorge, but a trek over the brink of the falls had never before been attempted.
Wallenda appeared fully in control through the stunt, taking small, steady steps on a slick cable through swirling winds.
"Oh my gosh it's an unbelievable view," he said as he crossed over the falls. "This is truly breathtaking."
ABC, the television network that broadcast the event with a five-second delay, 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."
The network had also insisted he wear a safety tether - a first for the performer - that would connect him to the cable should he fall, and said it would stop broadcasting if he unhooked it.
Wallenda fought the condition at first, eventually agreeing. But he gave himself an out: he would unhook only if directed to do so by his father, who designed the harness and acted as his safety coordinator.
As it turned out, the tether was never tested. Wallenda walked the wire with what appeared to be perfect balance.
ROAR OF THE FALLS
Wallenda said at one point that his hands hurt from holding the balance pole, and the walk proved physically tiring. The sounds of the falls blocked out noise from an estimated crowd of tens of thousands, he told the TV audience.
"Hopefully it will be very peaceful and relaxing," Wallenda said beforehand. "I'm often very relaxed when I'm on the wire. There may be some tears because this is a dream of mine."
Since the Great Blondin took his high-wire walk, a ban had 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 was part of the $1.3 million that Wallenda said he had spent on the walk.
Reyam Rashed, who moved to the area from Yemen last year, said she was most concerned as Wallenda neared the wire's low point, before he began walking back up the rope in the final push toward Canada. "I just felt like he was going to get dizzy," she said.
"At first, I thought he was not going to make it. I was impressed," she said.
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 would next prepare for a walk over the Grand Canyon in Arizona, which would be the first ever attempted and roughly three times longer than the walk over Niagara Falls.
"I just happen to have a permit," he said during an interview on ABC.
(Editing by Paul Thomasch and Peter Cooney)