Many foundation problems start out with usually a small crack in an exterior veneer wall such as brick. Chimneys, porches, steps, basement walls, and other exterior structures are areas that typically show problems before anywhere else. There are many causes to settling foundations but the main one is unstable soil.
Often homes don’t have a structural problem at all as compared to a settling foundation. This is considered non structural and most people, including structural engineers, can’t properly diagnose the problem.
Walls in many areas of your home can fail due to not being properly reinforced from the beginning. For example, a cinder block basement wall may have not been built using the proper width block, reinforced steel, or the block cells not poured with concrete. This can cause the wall to fail and bow into the home.