Ostia Antica - and we can't build bridges that last longer than 50 years?

Last Saturday our class went to Ostia Antica, an ancient Roman port village outside of Rome. I am posting the Wikipedia link up front here if you want to know the details about it: http://en.wikipedia.org/wiki/Ostia_Antica_(archaeological_site)

When we visited, it was nearly 105 degrees. I snapped a lot of pictures, but it was too hot to pause and read the placards in the broad daylight. To be honest, it was only my fourth day in Rome and in that heat, I really didn't care about the history.

I will say this, though, some of the buildings that are still standing were built in the 3rd century B.C. This means that they are 2,300 years old. The fact that one of our interstate bridges collapsed in Minnesota recently, and the I-90 bridge sank in 1990, and the Tacoma Narrow's bridge ("galloping Gertie") collapsed as well, is embarassing. Maybe our civil engineers could spend a few weeks here getting pointers from the Romans.