In the middle of the night last night, the hot end fell out of the extruder and woke everyone up as the filament kept extruding. The heater was unplugged, so there was un-cooked filament on the inside of the case. I think it got wrapped around the bed until the extruder was being pulled towards the edge of the printer, which caused the grinding noise. Then morning came and I finally had time to investigate further. Two of the twist-screws underneath the bed also came out, but they're not stripped. One of the springs was found on the bottom of the case. I really am not sure exactly what happened. It's all re-assembled and I'm about to re-do the Z-Offset and do a Benchy print. I think I have a poltergeist in my home.