Multiple gas lines?

[Dennis McCarthy]

Hello, everyone -- I'm a novelist doing research. In the story, there's a deserted six-story apartment building that is in condemned condition. Urban explorers and homeless people pass through there to party, to simply live, and so on. There are 36 apartments total in the building. My question: All the apartments had gas stoves, and all the stoves have been removed, but, surprisingly, all the copper piping is still there, exposed (the copper thieves haven't gotten to it yet). The hero of the story discovers that the negligent City Department never capped off the gas lines, and there is still gas available within the building! If he wants to turn the gas lines on, would there be one exterior valve to turn on, or might there be multiple gas lines in the basement? One member on this site stated, years ago, that he once saw a rent-controlled building that had separate gas lines to every stove (seems like a bad idea). In a very old, rundown building, were multiple gas lines common? Thanks! Dennis McCarthy