I'll check again. What's odd is that I'd successfully chain pieced at least 5 - 12" squares before that happened. Usually the thread would just break off at the top, it was actually shredded looking. But this time, what a mess!! I have this type of thing happen very very occasionally and it always mystifies me. Because things are going along fine and then - bam!!
Could I sew successfully with the needle inserted wrong for a while? I love my machine and I've looked at diagrams and videos of how it works, but it's still a bit of a mystery to me when things like this happen.