Nik Wallenda preps to cross Niagara Falls on tightrope Friday

In a few days, seventh-generation daredevil Nik Wallenda will walk over the Niagara River on a tightrope, the first person to do so in 116 years.

Crews on both sides of Niagara Falls are currently prepping for the event. Engineers, cranes and helicopters will work together to string the 7-tonne, 18,000-foot wire across the falls.

The Canada Border Services Agency is encouraging American spectators hoping to cross into Canada for the event to plan for extra travel time and to cross the border early in the day. Tens of thousands of visitors are expected.

Both Canada and the United States granted Wallenda an exception to Niagara's long-standing no-stunts policy, hoping that his historic walk will boost tourism.

"Not even Marilyn Monroe brought the attention here that I've brought," Wallenda said, referring to Monroe's 1953 film Niagara. "Anyone who says this doesn't help Niagara Falls, they're fools."

[ Related: Wallenda to confront wind, mist during walk ]

ABC will televise the walk. They are insisting the stuntman wear a harness, something Wallenda will accommodate as he doesn't want to lose sponsors. (As a general rule, sponsors don't want to be associated with a televised tragedy.) He did, however, comment that he has "never in my life walked with a harness" and needs the ability to detach from it if it compromises his safety.

Wallenda's walk won't be the first, but it will be the closest wire-crossing ever to the falls.

Niagara Falls' own history includes wire walkers such as the Great Blondin, who crossed the Niagara Gorge in 1859 with his manager on his back. Maria Spelterini (1876) walked across backward wearing wicker peach baskets on her feet. Charles Cromwell (1884) sat on a chair on the wire. Clifford Calverly (1893) raced across in a record two minutes, 35 seconds," writes Rick Hampson of USA Today.

Other daredevils included the legendary Annie Taylor, a 64-year-old woman who went over the falls in an airtight wooden barrel — and survived — in 1901. Bobby Leach did the same in a steel barrel in 1911.

Read all of the over-the-falls stunts, successful and tragic, here.

The National Post's Adrian Humphreys looks at the allure of the death-defying stunt. Why do we care so much? (And why did people object to the harness, essentially taking the possibility of death out of the feat?)

"It's not really about whether he can do it, it's about whether he lives or dies doing it. He is still doing something really cool but the real risk of danger is no longer there," Catherine Salmon, associate professor of psychology at the University of Redlands in California, told the National Post.

"People like to watch people who are willing to risk everything, people who take these risks and win."

She adds that we're fascinated by stories of violence — in this case, one man's potential tragic fall — "because we can experience the emotions without danger to ourselves and, also, it helps us to better understand the risks of our own environment. Watching violence and aggression is learning about what is successful and how to be successful."

Will you be tuning in on Friday to watch Wallenda cross Niagara Falls?