Buildings are constructed by humans and intended to last for a very long time. If you think about a force that may destroy buildings around you, you may think about explosives or devastating weapons.
When you walk through a decaying piece of industrial brownfield, you get to know a different type of destructive force: mother nature.
When a building is constructed, nature loses some area wich is now occupied by human beings. When those buildings are abandoned and left-behind, nature slowly takes back the area step by step.