For a few very long seconds, Alejandro Garibay thought the only thing between him and the street 103 stories below was the pane of glass quickly cracking as he sat on the Ledge on the side of Willis Tower.

"I had my palms on the floor and I could feel it cracking," said 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."

But he was never in any danger, according to Willis Tower officials, who said Thursday that only a protective coating cracked and the three half-inch-thick layers of glass underneath remained intact and still capable of holding five tons. The coating is about 1/8 of an inch thick.

"This protective coating occasionally cracks," said Willis Tower spokesman Bill Utter.  "Usually when someone has something sharp in their pocket and it gets poked.  It did what it was designed to do."

The Ledge was closed this morning for "routine inspection," but Utter said it was expected to reopen late today. The Ledge consists of four glass boxes that are extended a little more than four feet out from the skyscraper, about 1,350 feet above the ground.

Garibay, 23, said he and his brother had been visiting from Stockton, Calif. and his cousin had said they had to check out the view.

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

Saldana said he had been on the Ledge at least five times. "I told them this was one of the things they definitely had to check out," he said. "They're giving me heck about it now."

Utter said despite how the floor looked, there was never any structural problem with the floor.  "It's happened in the past," he said.  "We hope they come back."