Normal leaf drop would be the leaves turn yellow first, right? Wow. Have no idea. Can you take a closeup of leaves and new shoots? Also a shot of trunk near soil line?

It looks like it's in shock. Was there work done recently that would have affected the root area?

A couple of possibilities occur to me; either can lead to sudden wilting.

Burrowing rodents - I have voles that eat plant roots and even if they don't eat, the tunnels expose roots to air. Push firmly on the soil all around the plant to see if there has been tunneling.

Herbicide damage - There are two ways I've seen plants accidentally damaged by herbicides, via those spread on the lawn through something like weed and feed, and through drift when someone has been spraying upwind with a fine mist that has moved downwind to the effected plant.

did the weed free lawn get its spring weed and feed treatment???

ken

The type of herbicide used on lawns to kill dandelions and other broadleaved weeds are called phenoxy herbicides. Damage from overspray and/or drift presents as distorted, cupped, twisted and distorted foliage. I can't tell if this has occurred here or not. The leaf drop in and of itself would suggest something else. That is, unless these foliar distortions were seen first, then the leaves fell off. Any opportunity to send in a close-up shot of some leaves, either on or off the plant?

the height of the majority of the damage seems odd ... ken