Looks at first glance like a text book forced landing.
or possibly they missed the runway and crashed a servicable aircraft...? Think Polish presidential flight or Britannia at Girona. Difficult landings in bad weather,
The GPWS is likely to be a primitive one with warnings based on terrain closure rate rather than a database. So if they were coming down at 700 fpm on an NDB approach to a runway there would be no warning if they went for a road instead.