I also do not know how to reconcile that photo with this one:
http://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I00002lnQqBGT9AI/KG-oro-spillway-damage-10000-jpg
which has no sidewall collapse.
I’m just confused, I guess.
The second photo in 1811, the photo showing the collapsed wall, was taken later when there was greater damage. It was taken at about the same time as this photo:
h/t maggief for this photo.