Could be demons rushing. Could be whatever left that.

[He shines his flashlight over a patch of claw marks leaving a deep groove in the surface of the wall.]

There's no mildew built up there. It's fresh.

[Whether he can fix it is another matter entirely. He swings his pack over one shoulder and rummages through the supplies they've brought.]

I can cut away some of the damage and reconnect the strips to get the lights temporarily up. Might need to freshly install some parts for a more permanent solution.