I normally dont put this stuff off when I hear things like this but, the guy said it was probably 15 to 20 years ago when he saw them so I figured they were crushed out years ago and, I have never seen any signs of anything going on back there. It would also be to difficult to just kind of wander back there to take a peak but, now I have a reason to stop since I can use the cars by the building as a starting point in the conversation...