At this point the quest has been so aggravating I don't even care anymore about murdering the entire building. My issue is that the quest won't complete in my journal. It's just stuck there saying I need to find a way to the 3rd floor. I tried one more time without sneaking up. The only "sneaking" I did was to loot from the male Drow on the 3rd floor to grab a particular note, but other than that I just staggered my party at various points inside the building and started blasting. I made sure none of the people on the first floor (except the kid) died first on the off chance it was one of them escaping that was bugging out the quest. Not surprisingly that didn't work.
I truly hope they get this adjusted soon. It bothers me to no end having open quests in my journal through no apparent fault of my own. lol