This is great.  Those climactic scenes in movies that involve some important facility where the only way to get to it is across some chasm.  Invariably the bridge or whatever is destroyed.  Didn’t that always seem gimmicky?  Well, now there’s a reason for it to exist.  It’s nothing fancy, just to keep snow from piling up in front of the door.  At least that’s why it’s there in front of the seed vault.  I’ll sleep better