When the place I worked at closed, 30 of us were left with no place to go, so many people have left the area. We were like one huge family. Is hard to get to know 300 people closely, but since we all lived in the area and worked together, you bet we at least knew names or at the minimal, that his person worked at the facilities.
Upon the closing, many of us have opened FB pages. I have a Linked In page but I like to keep it professional. My FB page is to keep track of my old work friends. This way everyone knows where we are and what is going on and I don't have to answer the same questions many times over.