Tourists taking photos in the glass ledges of Chicago's Willis Tower, which hang 103 stories above the street below, got a hell of scare this week when it looked like the transparent floor beneath them was about to collapse. A protective coating covering the 1.5-inch-thick, 1500-pound glass panel cracked, leading those standing on the The Ledge at the time to believe the entire glass structure was breaking. The visitors to the observation deck were in no danger. Fortunately for them, the web of cracking extended only through the 1/8-inch-thick protective coating, not the glass itself. But the playful fear of heights people experience on the 103rd floor momentarily turned to real terror for a few people, and made us wonder: Just how much stress can glass support when it's hovering 1353 feet above the city? Turns out, unless a pair of white rhinos decide to take a Windy City vacation, The Ledge is going to be fine—it's even back open for business
It is about information including technology and different other topics.