LOL!! You sure those last two photos are of a maple and not an elephant foot? I have never seen a tree so completely devoid of any root system......it's a wonder it's stayed upright this long!

This is most definitely a planting issue, not a disease. Even a root rot would leave some remants of both structural and feeder roots. Was this tree grafted? And yes, it was planted far too deep. And no telling what the root system looked like at planting.

I would be very interested to know what - if anything - you find in the planting hole this tree fell out of.

WOW! that's weird,looks like it was originally planted in a 2" hole in a pathing slab lol.
I've no experience with burlap but what would happen if a caged synthetic burlap was left completely intact at planting?

You have GOT to excavate and take photos- I am also curious as to what was going on down there!

I see that and I think that one of two things happened. Either the tree was constricted somehow, of delayed graph rejection.

I have a relative that moved a small oak tree, then put a coffee can around it to keep the weedeater away from it. Guess what, they NEVER removed the can. About 10 years later their nice tree came down when a tornado went close by. While looking at the tree, I found metal was in the trunk, and asked about it. That's when the coffee can story came out. Now this tree probable did not have a coffee can, but it may have had nylon binding or some other constriction object that was not removed at planting time. I agree with digging up as much as you can to find whatever clues exist.

It also occurs that a graft can do this same thing upon occasion. The tissues never fully mesh and try to encapsulate one another, resulting in a spreading line of swelling. This can go on for many years before eventual failure. Some tree species are much more prone to this, than others. Which brings us to the question, what kind of tree was this.

Lastly, cross post to the "trees" forum with some pictures of whatever you find on escavating. There are professionals that spend time there that may be of more help.

Arktrees

You have GOT to excavate and take photos- I am also curious as to what was going on down there!

Me too! That is beyond curious.

Thats an amazing set of fotos...I was wondering if the area was regraded and built up for final grade with no consideration for trees that were planted prior. I would check any other trees i had in the vicinity for something similiar. WOW! That definitely belongs in the 'how not to plant manual'