'99 GT - tie rod end...came off?

[sonix]

I had a "thump" noise come from the front of my car this AM (turning at slow speed in a parking lot).
Got towed home and took off the right front wheel to find the tie rod end connected (as per normal) to the spindle - and the shaft, with jam nut - nearby (not connected). The jam nut is not loose- I couldn't move it with my finger. The male and female threads seem to be fine on both ends.

How on earth could this have happened? I'm fairly savvy with engine type items - but i'll admit i'm green when it comes to steering components. They tend to just "work". I assumed the tie rod end is securely mounted to the spindle -- can't really spin off that way. The shaft is fixed too (right?) and can't rotate. What am I missing here? I'm leery to just use a pickle fork, pop off the tie rod, thread it back into place, and pop it back onto the spindle. But nothing seems damaged...?
Is this "common" on these cars? Anything I should be looking for?

Thanks

 

[Fivefingerdeathpunch]

The jam nut may not move, but it could still have not been snug up against the outer tie rod itself which may have caused it to spin itself out over time.

I would remove the outer tie rod nut, pop it out and spin it back on the inner tie rod and bolt things back together. Then take it straight to a shop for an alignment, they will fix the toe and make sure the nut is tight.