You are not responsible for Act of God, but you are responsibler for your own action.
Act of God: how tree grows, how storm fell trees.
Act of Man: you were warned of the danger but did nothing.
总之,天下危险的事情很多,你要是连草木的事情都担心自己负责任,那么请不要买独立屋,一辈子住condo好了。