After leaving Little Lamplight for the 20th time after once again not being able to get into Vault 87, I headed in a Northerly direction. As I approached KT-8 tower, near the drainage ditch entrance, a big explosion occured in the sky. Vertibird parts then rained down. I scoured the area, killed the supermutants by the tower, but found nothing. What was that all about?
Have you finished the Waters of Life and talked to Rothchild and you still can't get into V87?
RE: Vertibird
There is a random encounter there that happens with a Vertibird although I don't remember parts; just the explosions, but I've only seen it once. Usually raining parts from the sky mean the Firelance encounter, but those are little glowing bits unmistakenly labeled as Alien Ammo. I'm surprised that the Vertibird happens before you've done the Waters of LIfe, although you may have done it already and are experiencing the bug that makes the quest mess up. If you play on the PC, I believe there's away around it if you do. It used to be in the wiki.