I am wondering if someone could let me know what the hell to do. I reversed my car off my drive today and noticed that a large (2ft x1ft) peice of concrete had disappeared from the driveway under my car. I got out and had a look and there is a vast emptiness under my drive. It looks about 10ft deep and seems to run completely under all of my drive (enough for 3 cars). The concrete drive where the hole has appeared looks no thicker than 3-4 inches but what the hell is it built on and what is holding it in place. What does this mean I need to do. Whatever it is i guess it's gonna be expensive. Any help greatly appreciated.