I cleared out the Super Mutants at Jefferson Memorial weeks ago, as I was just wondering and exploring the Wasteland. Now in the Main Quest, I'm prompted to clear out the Mutant threat for the Scientists (they are all looong dead already), and cannot 'complete' this part of the quest. I don't have a save dating back to before I went into the Memorial the very first time. Am I screwed?? Is there a way to trigger the 'completion' to this quest?? Yes, I am 100% sure I killed every mutant in and around the Memorial.

Help PLEASE!!

Never mind...found out there was a 'sub-basemant'.. Ooops!

No NO!! Now the game locks up when I try to return to the main level!! I can't open the door without the game freezing/crashing!!!! What now??