How do you fight a fire on Mars? In actual play, a theater full of people caught fire. As flavor text, I'd mentioned magnesium as a common metal in structural components on Mars. The building in question is sealed, in a city, but not under a dome. Ultimately, the fire will go out when it cools, exhausts its fuel, and when the oxygen concentration drops. Emergency services will still arrive though. What do they look like in a Martian city?
—Sometimes the delete key serves best.