Hello, I posed this event several months ago. I have had time to take a closer look at the carnage and now understand more about it. It appears what happened is the screw broke off inside the crank shaft and what remained of the screw damaged the threads in the CS. This CS is not stock and was part of a stroker kit from Eagle as part of an engine rebuild several years ago. Below is a picture of the inside bore of the crankshaft where the bolt goes. You can see the remainder of the sheered screw and nothing remaining of the threads. This seems very unusual and where the screw broke does not make a lot of sense to me. There is nothing else wrong with the engine, but I am looking at a full disassemble to replace the crankshaft at this point. The car only has 24k orig mi on it. Has anyone experienced this?