<<Haven't often heard of brake rotor failures except on some jet aircraft
with
steel brakes.  The problem seems to result from a landing where heavy
braking
was applied followed by leaving the parking brake set immediately after
landing.>>

Yep, I've seen that.  Seems like they almost shatter.  I'll look at this one
closely in the morning, but I think the "chunk" just separated.  I was in a
bit of a hurry to pick up my dog at the vets.  Rattlesnake bite.

Naf