When has eagerness caused the downfall of man?

I have an ignment for English in which I have to provide details and examples supporting a thematic statement I interpreted from the novel Frankenstein. For my statement, I chose: "When man's eagerness causes short-sightedness, his downfall is inevitable." I already have three examples: Napoleon invading Russia, Frankenstein's mother herself, and Brutus from Shakespeare's Julius Caesar. I need one more example; does anyone have any suggestions?