Brake noise went from clunk to a horrible grind in a hurry

We had almost the same thing happen on one of our trucks. Instead of the bolt falling out it broke off with the threads still inside. That was not an easy job to fix on the side of a dirt road, a few hours from nowhere, LOL
This was one of those times I was happy about my hubby buying tools.
Of course it was an odd size bolt. Hubby had to drill out the old bolt then rethread a bolt we had.