I have an owner-builder pool under construction. Excavation and rebar phases are complete. We just had some rain. After the rain passed and the ground started to dry, I noticed there is a layer (about 2 inch thick) of the excavated wall breaking off in some areas. Is this not something to worry about, or is it a sign that a larger cave in could be in progress? If the latter, should I take any action now to try to limit the cave in? The part shown in the photo is about 5 feet from the edge of my house.