Everything has been going well and I came home to this mess on the build plate. The print was supposed to be three spool adapters. I think the extruder mostly stopped extruding. (Just mostly dead...) Any suggestions on what might cause this?
http://i.imgur.com/iq03AgI.jpg
Here's another view after I removed them from the printer.
http://i.imgur.com/PcvxvbF.jpg
I have re-started the same print (from the file that's still on the SD) and it is almost done with no problems at all.