The loud pop booms and strange scent in the air that over powers the methane gets you looking out one of the drainage holes at a freaky purple storm going on in the outside world. Looks like the end of the world in fact and you are scared. It then rains a black oily rain. A torrent of it, filling the drainage holes. It gets all over you skin and it burns! It gets in your eyes and eats them. your screams echo threw the empty sewers. You die alone and the city dies above you.