The line was already single tracked. I was at Newtown Jct., waiting for SEPY to come south, with engineer SDF running.(I was on the PYSE) Earlier in the week, a Philly cndr forgot his keys, in a switch, and they were "recovered" by some vandals. The section of track, from Cheltenham north back to the connection on the double track, is dark. (don't remember name of CP, at this point.) Track speed of 49 MPH was being run, when SDF saw switch open. He dumped it, ran into switch, crashed into loaded gons of structural steel, and locos rolled. SDF walked away, and ironically, this happened to him previously, on the ATSF, which resulted in him quitting that job, to find a safer place to railroad. Go figure. Two dark territory, rollover crashes, from open switches, same engineer. My train was backed down to CP River, and parked, awaiting clean-up of wreck. They never did find those keys, and I never ran track speed on that stretch of dark track, again. Regards