Thumbnails. No border: thumbnail links to a 640 pixel image. Pink border: thumbnail links to bigger image. Blue border: left hand half of thumbnail links to bigger image; right hand half links to image description on the Wikimedia Commons.
Compare with "no dumping" photos in other parts of the USA. Historically Chicago probably had worse problems than other cities. They built the Chicago Sanitary and Ship Canal to divert the sewage to the Mississippi instead of dumping it in Lake Michigan. It is still not fully cleaned up - see this 2016 article in the Chicago tribune.
