Tornadoes are like upside-down drains. Water flowing down a sink spins as centrifugal force interacts with gravity. Similarly, when a column of warm air rises through cooler air, it can form a vortex. If that rising air contains fire, you get a fire whirl or, in extreme cases, a fire tornado—flaring monsters that can reach nearly a mile high and swirl flames faster than 200 mph.
I’ve photographed a fire whirl only once, and I hope I never see a fire tornado. I probably won’t. The only one ever conclusively documented occurred in 2003, after wildfires erupted near Canberra, Australia. Even so, scientists couldn’t confirm what leveled more than 500 homes until they reanalyzed photos of the damage in 2012.