The house in question is 33 years old, so I don't think that "pirex" is the problem. I saw the problem, and a few years ago, my friend had some water in her basement and paid someone to dig around the foundation in that area, and replace the drain tiles. Then they filled the area with white rocks. It seems evident that water got under the basement floor somehow, and caused that area to crack and lift. It's right in the area that she had fixed (or so she thought). She's still waiting for the insurance company to come up with something. I think she should hire an independent house inspector to tell her what the problem is. Looks like the guy who supposedly fixed the drain tiles, didn't do the job correctly.