That's the last part of Albania adventures. Thanks for traveling together! Part 1 of Albania discovery - ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-vvyoctzaGTQ.html
After Envier Hoxha died, many of these structures were destroyed by people. But for this place, I would guess it collapsed naturally because it was built in the middle of mountains, I can think of storms, inside the bunkers I saw water leaks and etc.