This is when you see cracks in your bricks because the footing the brick work sits on subsides. This is usually due to ground movement caused by a number of things; the drought, leaking pipes, poor drainage, or trees too close to the house. These can all contribute to damage footings. The best thing is to catch it early.
If your plaster is cracked and there is brick work on the other side it’s your footing that needs the attention not the stumps.  Some people tell us that there are not any cracks in their brick work just in their plaster. The damage will follow the path of least resistance and the gaps around the windows or door frames increase.