The glass deck, known as the Ledge, hangs off Chicago's tallest building and is a popular tourist attraction offering a thrilling experience and dizzying views of the city.
One California family got a lot more than they bargained for when the glass started to crack beneath them as they took in the city views.
There are four viewing boxes extending out more than four feet from the building's Skydeck. The three-inch thick glass is meant to withstand 5 tons.
Alejandro Garibay was in one of the four deck boxes with his brother and two cousins on Wednesday night when he heard cracking and saw what he thought was the glass splintering, reports theGuardian.
"A crazy feeling and experience," Garibay told NBC Chicago.
"We were watching the fireworks at Navy Pier," Garibay recalled to The Chicago Tribune. "It was an awesome view. We were getting up and walking away and for some reason I thought it would be cool to get a picture of my cousins and brother. . .Then we started getting off and, as we push ourselves off, I could feel it cracking. It was completely shattering."
According to the Daily Mail, staff told the Garibay family that the glass was unbreakable before they stepped on.
The glass viewing deck opened in 2009 on the 103rd floor of Willis Tower, formerly Sears Tower.
According to a Willis Tower spokesman, it was actually the protective coating on the glass that cracked, not the glass itself.
"The Ledge was designed with a protective coating that completely covers all glass surfaces to protect against scratches. This coating does not affect the structural integrity of The Ledge in any way. Occasionally, the coating will crack, as it is designed to, in order to protect the surface of the glass," Brian Rehme said in a statement.
Rehme added that the visitors were never in any danger.
Workers with MPH peeled the cracked layer of coating on Thursday and put in new glass and caulk, reports theDaily Mail.
The Tower's Skydeck remains open but The Ledge has been temporarily closed for a routine inspection. The attraction will reopen on Friday.
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