How the fire happens
So let's say the oil blowout continues, and the Gulf of Mexico is carrying millions of gallons of crude oil as a massive hurricane approaches. It's a hot July day in the Gulf of Mexico, with temperatures soaring towards 110 degrees, accelerating the evaporation of volatile oils which get mixed in with hurricane-force winds.
The hurricane makes landfall in New Orleans, let's say, dumping potentially hundreds of thousands of gallons of what is essentially "volatile fuel" on the city of New Orleans. Now, at first it's just a wet, slippery toxic mess that kills trees and grass. But what happens after the storm when the sun dries out the city?
All the dead trees killed by the oil turn into kindling. The sun evaporates off the rain water, leaving behind fuel. A few days of sun baking and you have a city doused in fuel, ready to burst into flames. It's every fireman's worst nightmare. The whole city is essentially turned into a giant match.
Now, sure, the more volatile fuels might evaporate, but as they do, they'd fill the city with explosive fumes. One spark, one fire, one lightning strike and your whole city literally goes up in flames. The BP oil spill, in other words, provides the fuel that could turn an ordinary hurricane into Mother Nature's arson attack on an entire city.