Like Your post but that baby picture freaks me outMark is right.Flooding will kill an oak quick,especially if it's not a swamp adapted variety like swamp white oak which that tree isn't. I"d say flooding did it.I doubt the work they were doing killed enough roots to hurt the tree.It appears to have plenty of unconstructed area around it.I was in the Bear swamp today,found about 30 more big Black Gum.Their all doing quite well and they seem to enjoy the flooding.
Thats me after the briars worked me over.Like Your post but that baby picture freaks me out