When building a home in the south, slabs on grade are a very common foundation under that house. As time passes there is a common crack that may occur that could make you panic if you see this crack. However, take a look at this video and rest assured - this type of crack is nothing to lose sleep over. (Granted, yes, it could have been prevented but right now I'm just trying to keep your blood pressure down). Corner cracks - take a look....