China's new glass-bottom bridge cracks - 3,500 feet above Earth

Suspended some 3,500 feet above sea level, a brand-new glass-bottom bridge clinging to China's Yuntai Mountain has left some tourists terrified. The U-shaped bridge spans across the mountain's face in Henan Province, giving tourists a chance to see the absence of ground between their feet and the sharp rocks below.

The creators of the bridge contend it's secure, with double-layered fencing and a triple-layered floor. Each glass pane measures 27 millimeters thick and each square meter can hold up to about 1,700 pounds.

Still, that hasn't stopped some sky-walkers from worrying -- especially since some news reports claim someone dropped a stainless steel cup on the bridge.

And that the glass then cracked.

PHOTO GALLERY: How China's glass-bottom bridge looked before it cracked

"When I was almost at the end [of the bridge] there was a sudden loud bang and a tremor beneath my feet," one woman told the state-run China Net, according to Agence France-Presse. Witnesses said some people started screaming and running to the ends of the bridge.

Mount Yuntai officials provided a much tamer account of the incident, which occurred Monday.

"Safety staff found some small cracks at the exit of the glass walkway during a routine check," the officials said in a statement. "An inspection has found that the cracks were formed by a sharp external object. The walkway is made up of three layers of extra strong glass and one of them has cracks.

"This does not impact safety."

Some people, however, remain skeptical -- especially on social media.

Lee Dong Hai, who claimed to be walking across the bridge when it cracked, said his foot "shook a little."

"I looked down and I saw that there was a crack in the floor," Lee Dong Hai wrote on the social media site Weibo, according to News.com.au. "A lot of people started to scream. I screamed out, 'It cracked! It really cracked!' and then I pushed the people in front of me so that we could run out of the way."

Another user, Li Donghai, said online that authorities were attempting to minimize the incident.

"The statement from Yuntai Mountain is wrong," Li Donghai wrote, according to the New York Times. "It was not just a few cracks in the glass. The whole pane had shattered. Saying that I'm making a mountain out of a mole hill is slander and I won't take it."

Yuntai Mountain's glass-bottom scenic spot isn't the first to take a hit.

When visitors at Willis Tower's Skydeck in Chicago stepped out onto its see-through ledge last year, some said they heard it crack. A spokesman at the time told The Washington Post it was only the protective coating that cracked, not the glass.

And in London, a layer on Tower Bridge's transparent walkway shattered when someone dropped a beer bottle on it.

Mount Yuntai officials said repairs to the bridge are underway.

"This happens every now and then around the world," they said. "To ensure that tourists are 100 percent confident in safety, the Yuntai area has decided to temporarily close the glass walkway to tourists. It will be reopen when it's been repaired. Thank you for all tourists' concern and support!"