Robert Benincasa, NPR

If they had known, they never would have bought the house on Bayou Glen Road. Sure, it was a beautiful lot, tucked in a bend of the creek, backyard woodsy and wild, the neighbors friendly and the street quiet. A little piece of nature just 20 minutes from downtown Houston. It was exactly what John and Heather Papadopoulos — recently married, hoping to start a family — were looking for in 2007. They didn't think much about the creek that ran along their yard, aside from appreciating the birds it attracted to the neighborhood.