Commenter Jonathan reported this closing, saying
Quizno’s on Sumter is now closed…The owner left a note on the door that he has closed immediately due to health concerns. He always had a smile on his face, and I wish him a speedy recovery.
Let me second those wishes!
This corner spot (on Sumter & Washington) is directly across from the old RCPL site, so I know I must have seen it many times over the years, and I know that it hasn't been Quiznos that long, but I'm drawing a total blank on what may have been here before, even to as basic a piece of information as whether it was a restaurant or not..