Even if you have a building, it will eventually turn back into dirt. Everything will degenerate eventually. A brick falls off here, a door comes loose there. Nothing can last forever.
As you watch the building degenerate, you can't help but think of your dad (だ). You had to watch him waste away the same way of a degenerative disease. Why do people have to die, dad?
Currently there are no similar looking kanji which exist in the WaniKani learning system