Cracks appear on floor of glass viewing platform in Chicago's Willis Tower

Visitors to Chicago’s Willis Tower, the city’s tallest building, captured video that appears to show cracks in the glass floor of its SkyDeck ledge 103 floors above ground.

A Willis Tower spokesperson told ABC Chicago station WLS that “no one was ever in danger.”

“The protective coating, which acts like a screen protector for the ledge, experienced some minor cracking,” the spokesperson said.

Nevertheless, the footage posted to social media earlier this week shows visitors looking somewhat alarmed.

The ledge is comprised of glass enclosures that protrude 4.3 feet away from the building, giving visitors a 360-degree view about 1,300 feet above the city, according to the attraction's website.

The spokesperson told WLS that the coating had been replaced and that the ledge is back open for business.

It's not the first time the coating has cracked. In May 2014, tourists captured photographs of the floor beneath them seeming to shatter. At the time, Willis Tower told reporters the protective coating is designed to keep the ledge from getting scratched up by visitors.

The 110-story Willis Tower, formerly known as the Sears Tower, is the second-tallest building in the United States.