Terror at 1,353ft: They said it was unbreakable but this was the horrifying moment Chicago tower block's 103rd floor glass viewing platform CRACKED under tourists' feet

• Family visiting from California evacuated from Willis Tower 1,353ft above the streets of Chicago
• Glass floor of tourist attraction The Ledge appeared to shatter beneath them
• Transparent viewing deck opened in 2009 on 103rd floor and the three-inch thick glass is meant to withstand 5-tons
• The Garibay family said that staff told them the glass was unbreakable before they stepped on
• Willis Tower spokesman said that although unusual, this has happened before and is perfectly safe
• All four boxes of The Ledge were closed on Thursday morning for maintenance
• Workers with MPH peeled the cracked layer of coating on Thursday and replaced it with new glass and caulk
  
• The attraction is set to re-open on Friday
  

By James Nye

Published: 12:37 EDT, 29 May 2014 | Updated: 03:37 EDT, 30 May 2014

It is what everyone who stands out on The Willis Tower's iconic Skydeck Ledge fears the most.

And on Wednesday night it almost came to pass when a family visiting the Chicago skyscraper suffered the scare of their lives when the glass floor of the tourist attraction 1,353-feet up cracked as they sat down for a picture.

The astonishing incident caused staff to hurriedly evacuate them as the distinct sound of shattering glass could be heard creeping across the glass enclosure that juts out from the 103rd floor of the building.

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Glaziers from MTH Industries finish replacing a layer of protective coating over the glass surface cracked on the 103rd floor of the Willis Tower in Chicago on Thursday

Terrifying: One of the four boxes of The Ledge, the 103rd floor tourist attraction atop Chicago's Willis Tower, appeared to show cracks Wednesday night, but a building official said what was damaged was a protective layer on the glass and that there was no danger to visitors

About to crack: Alejandro Garibay (center left), his brother Ernesto (center right), and two cousins (also pictured) in the glass enclosure just seconds before they heard the sound of shattering glass

'I had my palms on the floor and I could feel it cracking,' said Alejandro Garibay, who was posing for pictures at the time with his brother and two cousins. 'Honestly, I was in shock, in disbelief.  I was scared.'

'We were watching the fireworks at Navy Pier,' Garibay said 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.

'I thought there was only cracked glass between us and 103 floors down,' he said.

'One of the craziest feelings I had in my life,' added his cousin, Antonio Saldana.  'I thought I was going to fall through.'

Ironically, moments before they stepped into the glass viewing platform just before 10pm, the Garibay family said they were told by staff the floor, which can withstand up to 5-tons, was unbreakable.

'I was like, wow, I literally can't believe I could have fallen just through it,' said Alejandro to NBC Chicago, who was visiting the 1,451-foot skyscraper - the world's eighth tallest - with family from California.

'At first I see the glass from the ledge to the building crack and at that point I just hopped off.'

'I can' remember if I crawled off or I jumped off. Just a million things, I couldn't believe what was happening,' said Ernesto Garibay about his family's terrifying experience on Wednesday night.

'Even now I can't believe it, it's hard to believe.'

'Especially when they said it's unbreakable.'

The see-through glass bays known as The Ledge were designed with a protective coating that cracked on Thursday and glaziers are now working to replace

The attraction is scheduled to reopen on Friday after Glaziers from MTH Industries complete placing a layer of protective coating over the glass surface that cracked on Thursday

Aftermath: Technicians tend to the shattered protective coating that covers the floor of one of four boxes that make up The Ledge 1,353-feet up the Willis Tower in Chicago

Do not look down! Brave tourists step out onto The Ledge which juts out 1,353ft above the sidewalks of Chicago

The Garibay family were among the last customers on Wednesday night - paying $19 for dizzying views of downtown Chicago and Lake Michigan which can stretch for 50 miles on a clear day.

Stepping out onto the clear ledge, Alejandro Garibay said that his brother and two cousins began to hear the distinctive and in this situation, terrifying sound of cracking glass.

'All of us collectively start getting up, and it’s at that point that we hear and feel the glass start shattering. Mind you, this is happening in an instant. Incredibly fast,' said Alejandro's cousin, Tony Saldano to CBS News .

'We see it completely just shatter all the way through, and at that point, all four of us just completely rushed right out of it.'

Instinctively jumping off the platform, the Garibay's quickly alerted the staff.

'I walked them over so they could see and they were totally shocked and asked us to step away and then proceeded to start calling staff and techs and I don't know who else. When we pulled our phones to start recording and take pictures they asked us to leave right away,' he said.

Indeed, in video recorded by Alejandro, the ominous slow creaking noise of breaking glass can be heard.

On Thursday morning, all four boxes of the tourist attraction were closed for what a spokesman called a routine inspection.

'Skydeck Chicago is open today while the protective coating is being replaced,' said Brian Rehme, a spokesman for public relations firm FleishmanHillard.

'We have temporarily closed the four Ledge boxes for routine inspection we hope to reopen them shortly.'

Not for the faint hearted: Visitors are protected from the 103-storey drop by three inches of glass

Spectacular: The boxes that jut out from the Willis Tower provide never-before-seen views of the city, and allows spectators to see for 50 miles around

America's second tallest: The Willis Tower, formerly the Sears Tower, is the world's 8th tallest building. The four viewing boxes can be seen on the third windows down from the top on the left of the skyscraper

Rehme added that the visitors were never in any danger.

'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,' Rehme said in a statement.

Skydeck general manager Randy Stancik said the Ledge is safe but should give off 'the illusion that it’s not safe.'
'We hid the railings, we hid the structural steel — we want to give the illusion that it’s a little bit, ‘Can I take these two steps out of the building?’'he told the Chicago Tribune.

A spokesman for the Willis Tower said that what cracked was a protective coating on the top of three layers of glass one half-inch thick.

'Occasionally this happens, but that’s because we designed it this way,' said Bill Utter to The Chicago Sun Times.

'Whatever happened last night is a result of the protective coating doing what it’s designed to.'

Utter added that this is not the first time the protective coating has cracked.

Usually it is caused by a visitor having something sharp in their pocket that scratches or cracks the coating.

Workers with MPH peeled the cracked layer of coating on Thursday and put in new glass and caulk.

The attraction will reopen Friday morning after city inspectors check to 'make sure all repairs have been completed according to city code,' spokeswoman Mimi Simon told the Chicago Tribune.

Opened to great fanfare in 2009, The Ledge is comprised of four glass boxes that are suspended more than 1,300-feet above the ground.

They extend four feet out from the Windy City's most iconic structure and with transparent walls, floors and ceilings, provide tourists with the feeling of being suspended on air for those brave enough to peer down.

LOOK DOWN IF YOU DARE: FRIGHTENING GLASS VIEWING DECKS FROM AROUND THE WORLD

EdgeWalk CN Tower: Canada

Situated in the CN Tower's restaurant in Toronto - part of the experience is a glass floor, 1,122 feet above the ground level.

The glass is 2.5 inches thick and is strong enough to hold 14 hippos.

Step into the Void: France

Billed as the tallest attraction in Europe at 3280 feet, the structure was three years in the making. 

It includes five transparent sides made of three layers of tempered glass fixed with metal to a big support structure.

Grand Canyon Skywalk: USA

The horsehoe shaped glass-bottomed viewing platform juts 70 feet beyond the Grand Canyons edge, 4,000 feet above the floor.

It can accommodate up to 120 guests at a time and offer a bone-chilling vantage point more than twice as high as the world’s tallest buildings.

TILT on the 94th floor of the John Hancock Tower: USA

TILT is housed in 360 CHICAGO on the 94th floor of the John Hancock Tower and, as the name suggests, the enclosed glass and steel platform tilts visitors forward for a unique perspective of the city 1000 feet up.

The attraction, which costs $5 to tourists and is thought to be the first of its kind, holds up to eight people, with the platform slowly moving outward to an adventurous angle above the Windy City