A very sad accident.
If one 'good' thing comes of this, let it be a salutary lesson to all power pilots who disregard gliding site locations, this is what
happens when an aircraft flies into a winch cable.
I've seen many aircraft transit overhead winch launch gliding sites at less than 1500ft, indeed one instructor had an aircraft come underneath him while on the winch launch.
Squawking 7700