One of the ledges at Skydeck Chicago, the 103rd floor tourist attraction atop the Willis Tower, appeared cracked Monday evening, prompting the building to replace the ledge's protective coating, a spokesperson confirmed.
Jesus Pintado said he took his parents and family members to the attraction, and while they were waiting in line they heard a "boom." A ledge with a woman and two children on it appeared cracked, Pintado said.
Terri Cornelius, a spokeswoman for Willis Tower, said the cracks happened in a protective layer on the ledge, but no danger was ever present for guests.
"It's like a screen protector," Cornelius said.
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Cornelius confirmed the protective coating was replaced late Monday night, a process that is also done annually, and reported as "business as usual" Tuesday.
This isn’t the first time such an incident has been reported at the Skydeck Ledge.
In 2014, officials closed all four boxes of The Ledge for inspections after cracks appeared in what officials said was a coating designed to prevent scratches on the glass. The protective coating was replaced at the time, according to a spokesman.
When the tourist experience opened in 2009, engineers said the boxes were composed of three layers of glass each about one half-inch thick. They were built to hold five tons, officials said.