Back in 1994 a neighbor city, Albany, GA, experienced massive flooding. For a couple months after the waters receded, sinkholes opened up under houses and cars driving along roads in the formerly flooded areas. Waters filled underground caverns making them only stable with the water still in them. Without aboveground wanter coming down, these caverns dried and became unstable again.

Looks like in the Atlanta area sinkholes are starting to happen.

A sinkhole caused by the recent rain swallowed up a car and driver in Gwinnett County Saturday.
The sinkhole opened up at the intersection of West Liddell Road and Club Place earlier in the week.
Police blocked off the intersection, but someone moved the cones and the motorist drove right into the gaping hole early Saturday morning.
The driver suffered minor injuries, but the car is stuck in the deep hole.
Police have blocked off the intersection again.
– See more at: http://www.wsbtv.com/news/weather/sinkhole-swallows-car-in-gwinnett-county/

I wonder why news agencies are not warning people to expect these might happen? Maybe the ground under Atlanta doesn’t have as many caverns compared to Albany so the danger is not as great? Hopefully it won’t take several of these for people catch on to the possibility.