Predicting sinkholes is something that has escaped even the best technical experts. That is something that can't be determined with any accuracy. That said, this issue needs a professional evaluation. It is important for you to have all the facts before making any repair decisions. The first step we recommend is to have an inspection done by a professional home inspector that is certified by the American Society of Home Inspectors, or ASHI. You can find one in your area by using a locator tool on ASHI's website. Another option is to hire a structural engineer. I do not recommend hiring a contractor. At this point you need an evaluation, not a proposal for repair. Any evaluation made needs to be independent of any conflict of interest in offering repair advice. Keep in mind, it's not unusal for homes to settle including slab foundation. There are many questions you should be asking. For example, is it active or inactive? In other words, is it continuing to move or not? Or did it just happen slowly over many years due to normal settling of house. All of these questions need to be answered by a pro… and only then will have info you need to move forward.