I've done some small retaining walls all under 4ft. A referral lead me to this job. It's sad. Inside the wall is a swimming pool and deck that are both failing big time. I suspect the pool leaking has a lot to do with the amount of recent damage. Also the owner bought this house two years ago. So there are a few people that should be held accountable. One being the inspector who passed this house before closing 2 years ago. I've got a structural engineer looking at it but I'm not going to be the first to bid on this job. There are so many things that can go wrong. Any mistake would be costly. It's just a matter of time before the city steps in. I wouldn't be surprised if they condemned the property.(or something) Notice the gas line!