A teenage girl fell through a sidewalk in Xi'an, the capital of the China's northwest Shaanxi Province, after she failed to notice warning signs. A video of the girl walking along the sidewalk and using her cellphone on March 25 has been posted to YouTube. It has been generating lots of interest on Tuesday, April 24, 2012. (YOUTUBE SCREENSHOT)

A teenage girl walking on a sidewalk in Xi'an, the capital of the China's northwest Shaanxi Province, fell six metres into a sinkhole.

The video of the accident, that happened on March 25 but just started making the rounds on YouTube this week, shows the sidewalk suddenly crumbling under the girl's feet, swallowing her up.

A cab driver named Wang Wei stopped and jumped in the hole to help her out, China Central Television reported.

Local media reported the road surface in the area had been eroded by underground water. Firefighters had to use a ladder to help the two get out.

"The ladder didn't seem very stable, and she kept screaming out of fear. So, I soothed her, saying that I'd follow and protect her till she climbs out of the pit," Wei said.

The video surfaced just weeks after another video showed a woman falling through a sidewalk into scalding water. Yang Erjing, 27, suffered burns to 99% of her body when she fell through a sidewalk on April 1 in Beijing. She died April 9. Officials have said corroded pipes were likely to blame for that sidewalk collapse.