Sinkholes are caused when saltbeds or soluble sedimentary rocks below the earths surface erode. The pressure of the ground makes it collapse, creating what appears to be the "sink hole."
Approximately 25 people have been evacuated as a result of the sinkhole in Germany. Experts say that the cause is natural but have not elaborated on the creation of the sinkhole.
See the video below about the German sinkhole 2010, what do you think?