Depending on the kind of horror movie this is, we're either all screwed forever, or there's some kind of ritual that can be done to let them rest. Giving them their graves back, or something.

[ Of course, this isn't actually a horror movie, but they're as good a reference for how to deal with vengeful spirits as any. What Nanoha learned is how to exorcise them. (With really powerful magic.) ]

But first, let's get away from the intersection. This place can't be safe.