The first signs of drought are usually early leaf drop as the plants attempt to slow transpiration. It usually takes considerably more than a year of drought to cause severe damage to established trees,

Some trees also just have much stronger branching and crotches than others.

i know some trees especially those in the bradford pear family are prone to wind damage. i guess the damage was done during the storm & it took this long for the limbs to fall.

It's too bad, looks like rather nice trees, I don't know how resilient hackberries are to rot in which in time will get within those large open wounds.

where are you big city name... how bad has the drought been...

the structure of the tree is wood .. aged.. mostly dry interior wood... i really cant conceptualize how drought would after such ..

it wont change crotch angles... general canopy structure.. etc ..

this is a rather interesting link: https://lotusmagus.com/hackberry-tree-pros-and-cons/?expand_article=1

until you get down to this part: One of the biggest issues with hackberry trees is the unpredictable nature of their branches. They seem to fall off randomly, making it not an ideal choice for a front yard tree.

===>> so we would be back to my premise.. that drought wouldnt alter structure...

ken