What are the signs of the wall falling down-I know, talk about it recently.

This has nothing to do with your father's illness. The first possibility of this stone coming down: it has nothing to do with the whole wall, but this one, because it was inevitable that it was not cut firmly, for a long time, washed away by rain, shaken and other factors. Secondly, there may be a problem with the whole wall, so take the lead. So you should take a good look at what has changed. Pay attention to changes as soon as you find them. If necessary, we should try our best to prevent falling.