A childhood belief about in the street

When I was little, I was that kid, the one asking all the endless, annoying questions. One day, I was inclined to ask my mom what in the world was beneath the streets. I mean there’sdirt under grass and every kid knows if you dig long enough through that you'll hit China, but what happens if you dig up the roads? So I posed this question to my mother who replied that there was water beneath the pavement. She failed to elaborate on this point with a statement such as “There are big man-made metal pipes with water in them in order to provide citizens access to running water” so I was convinced that there were oceans under the roads. Oceans. And what do oceans have in them? Freaking SHARKS, that’s what. For half of my childhood, I was convinced that if there ever was a problem with the roads or an earthquake tore up the surface or something, it would open up to these Hellish oceans, and we would all drown in a deep sea of marine life and be eaten by sharks.