If you have clay soils around your home, they can expand and contract significantly as they become wet.
Wet clay soils can expand enough to put literally thousands of pounds of pressure on a foundation wall. This can force the walls inwards, sometimes causing them to buckle and crack. Look also for walls pushing in at the bottom or tilting in at the top.
If left unrepaired, this kind of damage can worsen until the wall fails completely or is beyond repair. By addressing the problem of failing walls quickly, repairs can be completed in as little as a day.