Part of B&M railroad, this was the repair yard. Pan Am Railways is still located here and in operation across from the repair yard so the site is still somewhat active. A lot of the "goodies" like old trains, buses, tracks and signals are now gone as there is a clean-up initiative going on. I haven't been there in over a year so I'm not sure if they've taken out some of the old machines inside the building.
Some have reported running into the cops while they were there but I've been multiple times without a problem. It seems to be a pretty easy explore since the building is wide open.
**Updated 4/29/11** Went there today to take some shots of my car and while I was there I noticed they've installed a camera on one of the doors at the front. Don't know about the back.