Quote Originally Posted by Rosenstrauch View Post
I think the whole "nobody saw it happen" bit is meant to imply that there was no crash. Rather, the Puppets' Bunker was underneath the mountain the entire time. Even so, those sort of circumstances would be difficult to understand too. Really, it doesn't make sense either way.
Perhaps it happened on the day of the Flood, when eyes were elsewhere, and the barriers between planes of existence were at their thinnest.