I would guess it was left over night. Even thought most people won't do anything to prevent a bike theft, and Seattle is an especially passive aggressive place, it still seems pretty brazen to do in broad daylight.

On the other hand, I suspect someone with an allen wrench set was probably walking around the university district looking for easy targets. I don't know whether the same thief took the saddle/seatpost and the fork or not, but I locked a bike up years ago and the seat was stolen. People take those, and a lot of them need a $5 tool to get. Someone with bike knowledge might have been up to minor no good, saw a shock absorber on the fork, and realized that you can undo the headset and stem in half a minute. That would even explain why the front wheel was gone and the back wasn't.

I'm not worried about this, personally. I just saw a bike that had seen hard times, and started to wonder.