Question for diesel gurus (strange failure 6.9idi)

I had a 85 F250 4x4 with the 6.9 in it.

One day i was changing the glow plugs and one snapped off. I thought about it and just put the new one in.
I let the engine eat the old plug.
They are hard to kill.

These engines have a prechamber for the glow plug and it would have most likely have trapped any serious piece of the glow plug and it would have eventually broken up and passed out of the engine.