So my neighbor's wall collapsed into my backyard....and now they want me to fix it!

[FarmerJ]

Xylene I suspect to begin with it may have been someone trying to squeeze two parcels out of what really should been one very large parcel and little thought may have been given when someone chose to put the OPs home right where they did. To the original poster documentation like video ) is going to be your new friend and not only take a lot of pictures but perhaps do long hand notes or voice record what you see as conditions EG , it rained last night real hard and the rains caused what looks like a gully /crevice from the top of the hill ( as you pan the camera lower) you can see where the water began to wash soils from the hill down into the _______ part of my yard.