The underground explosion in New York City should make us all think about our cities. So many of our cities have underground pipes just like they do in New York City. Many of these are very old. It is a little disconcerting to think that walking around a nice city could be dangerous. Let's see, we have crime, accidents, and terrorism to worry about. Now we must wonder what is going on UNDER our cities. It is astonishing to think about the age of the pipes in New York City. The underground "city" may be a disaster waiting to happen. Is what happend just an isolated incident? Maybe. But when considering the age of all this equipment, this could happen again. Who knows what could happen next time. There are many cities in this country with similar underground systems. Apparently, it is far too expensive to completely replace these systems. So what can be done? Do cities replace one pipe at a time? Do they keep their fingers crossed and hope? If something like this happens in New York City what do other cities think? It is like sitting on top of a volcano. Who knows when the volcano will blow? Look out below!