I think the house next to mine might be getting demolished without a permit. Who can I call?

It’s suspicious to me that even though the house is completely gutted, floors and all, you’d never know from the exterior. The curtains on the front are drawn tight and they’re leaving all the debris in a 6+ foot high pile in the backyard. From my yard I can see the whole empty frame of the structure.

Not trying to tattle but I share a wall with this house and I’m getting paranoid about those horror stories of places collapsing.

Thanks!