Check this out.  A sink hole in action.  It occurred underwater in this lake swallowing up the shoreline.  The explanation of why it occurred is frightening.
http://video.foxnews.com/v/262.....ut/?intcmp=obnetwork

WOW

same thing is happening in Fla....take your chances when visiting.

Don't buy salt.

It is not really that unusual.  Florida and the Gulf Coast, all of which used to be under the ocean, sits on top of limestone (old ocean floor) which erodes very easily, and causes sink holes to occur.  It probably was not wise to build up that area which will inevitably go "back to sea" from where it came.

That, boys and girls, is what planetary evolution looks like.