Hey mark,
if the entire street is planted with these and they are about the same age then this is what you will probably find"
<ul type="square">[*] The original wire basket, twine or burlap still around the root ball
[*] SGRs
[*] Compression injury of the trunk and limbs at major unions especially where opposite buds over time have pinched the original central stem
[*] old sunscald wounds/crack
[*] vascular scorch as a secondary problem
[*] and if any contact with the primary wires or worn secondaries, then cellular disruption due to the electrical current, no matter how small, flowing through the tree.
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All of it stemming, originally from the first two issues.
We see it here all the time and when one gives up the ghost it is almost a sure bet we'll see half of them going within a few years.
If I were a betting man I'd but my dollar down saying that if you dig deep enough you will find the basket still on the root ball.