Four-Day Planet by H. Beam Piper

The moaner went on for thirty seconds, like a banshee mourning its nearest and dearest. It was everywhere, Main City Level and the four levels below. What we have in Port Sandor is a volunteer fire organization -- or disorganization, rather -- of six independent companies, each of which cherishes enmity for all the rest. It's the best we can do, though; if we depended on the city government, we'd have no fire protection at all. They do have a central alarm system, though, and the _Times_ is connected with that.

Then the moaner stopped, and there were four deep whistle blasts for Fourth Ward, and four more shrill ones for Bottom Level. There was an instant's silence, and then a bedlam of shouts from the hunter-boat captains. That was where the tallow-wax that was being held out from the Co-operative was stored.