I thought these photographs were fascinating - a workman clearing the 911 site made a record, the photos (on CDRs) were found in a house clearance sale, some were in bad shape and needed a data recovery company to extract the data.
https://www.flickr.com/photos/textfiles/albums/72157708997281912/page22
I think they are all the more interesting because they were obviously taken by a contractor and have a quality / work perspective to them that I haven't previously seen before in (professional) photos of the aftermath.
A bit of the back story is here. I really hope they remain on flickr (or freely available online) and don't get pulled - they're an important archive, how time flies this is now passing into history..
https://www.bbc.co.uk/news/technology-48689783