Unfortunately, with today's real estate market being so depressed, this upside down equity situation is a common occurrence. The financial burden put on families during these times only makes a bad situation worse. In many cases it can be the culprit that helps lead to divorce. There are no "simple" answers to this complex problem. Numerous issues need to be analyzed. You need to be advised by a family attorney as to the potential options. An experienced family attorney deals with these types of matters on a daily basis. You cannot put a price tag on piece of mind!
