Buggington, it was sudden and unexpected. There were no symptoms that I had noticed, though I've only been riding this bike for about a month now, and I'm not sure what it's been through.
fietsbob, one assumes correctly.
I ended up going to my LBS and getting it replaced for $15. While I was there they also found me a pannier rack that actually fits my bike, so that was a bonus!
Thanks again, everyone!
