Our 15th floor hotel room looked out across rooftops, with the Empire State building in the background. Not a bad view, especially for an urban sketcher! One morning we found a crew of workers installing a new wooden water tank across the street. They were climbing around on make-shift scaffolding 120 feet off the ground, with no sign of any fall protection. I was a nervous wreck, and I was just drawing them.
The water tanks are a picturesque feature of many rooftops. They look quite incongruous against the stylish old and new architecture, but they make a lot of practical sense.