I was on my way to the ferry at Dover for a weeks touring abroad when the rear bearings went, just after the sun had gone down. Initially it felt like I was riding over a concrete road with a gap between the blocks, bump bump bump. Tyre pressure was, so checked for play and it was that. Called the AA and when the bloke came he said bearings gone, but couldn't give me a lift to Dover as he didn't have the kit to tie it down or some other such excuse. He said ride slowly, it was only about 10 miles, he would follow behind. So I rode to the B&B, it made hell of a din screeching. Next morning took it to a bike repair shop and they said the heat generated had welded part of the bearing to the wheel and would have to get the welder on it to heat it the bearing up to free it, it might ruin the wheel, was it ok for them to continue? Luckily they managed to fix it with no damage.
I'd never ride a bike anywhere again if that happened again, as much from the safety angle as damage.
I was going to take it up with the AA but when I got home from holiday had dismissed it as one of those things.