A man steps on a sharp piece of glass, He gets a VIRUS from the infection called gang green, eventually he dies, after the body decomposes the virus goes dormant and forms into flu, years later a worm eatsthe dirt contracting the flu, a bird eats the worm contracting bird flu, the bird dies and a pig eats it contracting swine flu, Next a human eats the pig contracting Homo flu, Then an alien eats the human and contracts space flu, after that it eventually spreads threw the galaxy then the universe. Until there are no living things left.