Imagine walking down the street and the ground below you caves in. That happened to a teenage girl in the northern Chinese city of Xian in late March. Surveillance video of the incident has  surfaced showing the girl talking on her cell phone - then all of the sudden falling 20 feet into a sinkhole.

A passing cab driver named Wang Wei saw the incident and tried to help the girl, falling in as well. Firefighters were called and eventually pulled both the girl and cab driver out of the hole using a ladder. The girl's family used the video to track down Wang and thank him for his help.