text: Probably the automobile- killed more people than anything else.\nIt's an outstanding question- deserves an outstanding answer.\nI dont know if there is one singular invention that qualifies, but\nin all seriousness, if I had to give one answer, it would be the\nhydrogen bomb. Has no other purpose than to kill zillions, wipe\nout the entire human race. It is not a "useful" invention in the\nsense of harnessing its' energy or anything like that- its just THE\none most destructive thing ever created/invented, no?