Always love good engine metaphor. For those that are unaware, when you throw a rod as the title says, the engine is normally irrepairable. There is so much damage inside the cylinder itself from the loose rod slamming inside that boring out and resleeving the cylinder will not work as the walls of the cylinder become too thin and could easy overheat and cause a coolant and/or oil leak, caviation, etc, etc. The second part of throwing a rod is the rod will blow out the cylinder wall with catastrophic damage that cannot be repaired, it's doesn't matter if you are the worlds best tig welder with a miller dynasty 400, it can be difficult to match the core material -- it cannot be repaired.

The metaphor is this simple, they are done, and you are watching the slow down till failure is complete.

I had this happen in an old toyota I had, always well maintained, but damn if it didn't throw a rod in the #2 cylinder, long story short, I left a lot of oil on the street, and I was putting in a new 20R engine a month later.