Ohio Rev. Code § 723.49: Damage from excavation.

If the owner or possessor of any lot or land in any municipal corporation digs, or causes to be dug, any cellar, pit, vault, or excavation, to a greater depth than nine feet below the curb of the street or streets on which such lot or land abuts, or, if there is no curb, below the established grade of the street or streets on which such lot or land abuts, or, if there is no curb or established grade, below the surface of the adjoining lots, and by such excavation he causes damage to any wall, house, or other building upon the lots adjoining thereto, such owner or possessor shall be liable, in a civil action, to the party injured, to the full amount of such damage. When there is a curb or established grade, the depth of such excavation, at any point thereof, shall be measured downward from the pitch line projected laterally over the lot or land, from and between the corresponding points in the nearest curb or established grade opposite the ends of such pitch line.