Going a bit deeper, the earthquake took out most of the water supply to the fire hydrants in the city, and so the fire department couldn't put out the fires tha

Going a bit deeper, the earthquake took out most of the water supply to the fire hydrants in the city, and so the fire department couldn't put out the fires that started during the quake. As a result, SF now has a backup hydrant system! Those big fat multi-colored hydrants are all connected to a fire-only water system that's gravity-fed from cisterns all over the city. The colors of the hydrants encode information about which cistern the water comes from, IIRC. And whenever you see a random arc of a circle made of brick inlaid in the road, that's outlining the location of a cistern. https://www.atlasobscura.com/places/the-golden-fire-hydrant https://www.atlasobscura.com/places/the-golden-fire-hydrant https://www.citylab.com/design/2017/05/the-sublime-subterranean-cisterns-of-san-francisco/524853/ https://www.citylab.com/design/2017/05/the-sublime-subterran...