a sub-division of homes with stepped properties, retaining walls that create a stepped look. the home inspected, on the north west side the retaining wall has two large step-cracks. 1 inch space and it has shifted 3/4 inch inward. the retaining wall on the south side looks good or even recently rebuilt. the south west corner of the home has two V-cracks inside. where the cracks are located its obvious this one corner has settled or the earth has shifted. 30 feet west side of the home is a gully and no retaining wall but drainage for the property was located here.
what type of specialist do you refer for this situation