An example of how this story has gone viral is that over in the Forums where I posted this article it received nearly 2,000 page views yesterday:

South Korean couple disappear in freak sinkhole

Seoul (AFP) – Concerns about public safety standards in South Korea have been fuelled by shocking CCTV images of a young couple being swallowed up by a sinkhole that opened at their feet on the sidewalk in Seoul.

The footage, which has gone viral on social networking sites, shows the couple plunging through the paved sidewalk, shortly after alighting from a bus in the South Korean capital, as other passers-by look on in horror.

The incident happened near an apartment construction site last Friday — the end of the three-day Lunar New Year holiday.

Firefighters rescued the young man and woman who fell 10 feet (three meters). Neither of them was seriously injured and both were discharged from hospital after receiving treatment.  [AFP]

You can read more and watch the video at the link, but at least these two pedestrians are alright unlike the 16 people killed and 11 injured during the outdoor concert in Pangyo when the grate they were standing on collapsed.