CHICAGO (CBS) — Crews worked overnight to install the first high-wire cable that tightrope walker Nik Wallenda will walk across on Sunday, 50 stories above the Chicago River.

Barry McSweeny’s apartment at Marina City has quite a view for Wallenda’s high-wire act.

“It’s being publicized in 220 different countries, and different people are texting me, or sending messages on Facebook, just saying ‘Just excited about it,’ seeing if I have a view of it, and I do,” he said.

Wallenda’s father, Terry Troffer, supervised as crews worked overnight to secure the steel cable Wallenda will walk across on Sunday, 50 stories above the river. In the daylight it’s possible to see the network of cables and lines supporting the system.

Wallenda will first walk from the west tower of Marina City on the north bank of the river to the Leo Burnett Building on the south bank, with the wire at a 15-degree incline. It will be the highest and steepest high-wire walk in the history of the Flying Wallenda family.

He will then be blindfolded for a walk from the west tower of Marina City to the east tower.

Wallenda has been practicing for months in Florida, impressing Chicago organizers with a calm, low-key demeanor about the walk.

“It’s something he’s done his entire life. At age 2, he was walking the wire,” said David Kennedy, deputy director of the Chicago Department of Cultural Affairs and Special Events.

Strong winds were gusting early Friday as crews were installing the tightrope. Wallenda said he trains in 90 mph winds, so he’ll be ready if it’s another windy day when he makes his walk on Sunday.

Kennedy said the city has been working with Wallenda for about a year to plan the event.

“A bad reference, but he’s very down-to-earth. He’s very grounded,” Kennedy said. “The thing that impressed us is that he said, ‘Listen, this isn’t dangerous to me. My family’s been doing this for 200 years. I’ve been training for 40-plus years doing it.’ He wouldn’t do it if it weren’t dangerous.”

Kennedy said the city does not know how many people to expect for such an unusual event in Chicago.

“We don’t, but we’re super-excited about it. This is going to be shown in over 220 countries, but like any major event in Chicago, we’re prepared. We’ve got a significant amount of police resources, and the Fire Department. They’ve done great; Bulls rallies, Chicago Blackhawks,” he said. “We can handle the crowd.”

McSweeny said residents at Marina City have been told flash photography is not allowed during Wallenda’s walk, and residents may not grill on their balconies. They’re also banned from using drones or laser pointers, and each resident is limited to no more than eight guests.

If you want to check out the stunt in person, a viewing area will be set up on Wacker Drive, between Clark and Dearborn streets and between State Street and Wabash Avenue.

You also can watch on skyscraperlive.com, or on the Discovery Channel, starting at 6 p.m. Sunday.