I love these types of behind the scenes videos of cities. There is so much more that goes on to operate a city than most people pay attention to. But big cities are complex, and we take it for granted how smoothly things like flushing the toilet or turning on a light are.
So many times in New York, I see vehicles or boats from a particular city department that I didn't even know existed.
Here's a vid not for the sensitive. I'll just post the link...(3 vids)
https://www.youtube.com/watch?v=ZiNiBZiR_uA