I spent hours trying to clear the building but then I realized it was horde night and I have blood moon set to nightmare with 64 zombies so there was NO way I could survive in that hospital during a Blood Moon. I didn't want to throw away all of the time I spent on it so I had an idea. Maybe if I did stay in there any POI quest zombies still in there would come find me and I would be able to clear the building. So I went God mode and used up all of my ammo and then used my sledgehammer until they were all history. I killed hundreds of zombies but when it was all over THE PLACE STILL WASN'T CLEAR !!!
So I give up. I wasted thousands of AP and HP rounds that I spent so much time and resources crafting. That's the second Tier V that I haven't been able to clear no matter how many hours I spent searching the buildings. I thought for sure staying in there for a Blood Moon would draw any stragglers out. I even changed floors just in case they were trapped on one of the floors.
HAS ANYONE BEEN ABLE TO CLEAR A TIER V QUEST IN 21 ?