My guess would be that someone tried to get into your car with a "slimjim" - GM linkage is designed to break away of specific tools are not used to try and open it that way. Unless you were in there and bumped the linkage out.
Not sure this will help:
http://ocnav.com/cars/Sky/part_nums/Door.pngIt looks like there's 3 links for the lock -
18 - lock motor / door hitch mechanism
19 - door button link
24 - door handle link
25 - door lock cylinder link
If the interior (manual) door button still works it's probably part 25. If not - the whole works might have come off the motor.
Here's the lock:
http://ocnav.com/cars/Sky/part_nums/Door1.pngHere you can see the "fork" (part 9) that the linkage connects to...
It's also possible that you popped off the end of the lock (parts 10 & 9) and that would in effect disconnect the locking mechanism as well - but in that case I would expect that the door would not lock at all.
If you need specific part numbers let me know and I will pull them.
On a side note: wow - this program has some BUGS - it crashes way too often - I do not think I'll be able to print to a PDF. I may try loading it into a virtual machine to see if a "cleaner" OS helps....