Neighbor took our fence down??

💕

We have a fenced backyard- yesterday I look outside and see our fence is gone! It looks like they may be rebuilding the fence at the house behind us bc I see lumber in their backyard... but I can’t let my pets out now in the backyard! We are renting a house but I’m sure our neighbors behind us who removed the fence didn’t know that and they didn’t even check with us... just super weird to me! Does anyone know if this is legal?