The black appeared to be a tar based waterproofing spread on the inside of the cinder block foundation. I think the conductive paths were spider webs.
The recess was about 16" deep.
The panel was supposed to be relocated near the red curtains on the right side of the photo.
I don't think any circuits were labeled so I don't know what the tripped breaker fed.
Like Randy I think that this was installed after the meter and panel were already approved. The SE between the panel and meter was not strapped, but I don't remember if the incoming line was strapped or not.
