What’s the correct emergency procedure for when a sink hole opens up underneath you? Answer: there is none. The ground opens up a big black hole of death and you fall inside and die. Nothing you can do about it:
These people in Yongsan, South Korea didn’t actually die though, so that’s good news. Easily could have though. Instead they were trapped inside for 20 minutes and both sustained leg injuries before being rescued.
For more insane sink hole footage, check out this one opening up and swallowing an entire street.