.
Had that happen on my XR2 turbo, there the same part as on the Escort, Mine was being used as a track car at the time, when I took it apart the bearing was fine and had been on there a few years, I read it's quite common on Mk3 & 4 Escorts and Mk2 Fiesta's that get track use. I just put it down to heat build up. Mine used to get the usual pre track checks and bearing greased and hub nuts re-torqued to correct poundage.
P.S this happened to mine at Fiesta in the Park about 4 or 5 years ago, thought the bearing was gone, the bolt seamed loose so tightened it up and drove it home which was 250 odd miles away in Cardiff and bearing was still in one piece. so can't say it was bearing failure.
Ginger.
.