This image rendered for three days on 4 computers before crashing, and losing all the work. I rendered again at wallpaper sizes only, just to get it online. I may never try rendering a commercial version of this one again.
This one has been sitting unfinished for a year, because the gray blast wave didn't like mixing with the fire, and kept crashing the computer. I figured out it would render once per loading of the image, only crashing the second attempt. So I reloaded after each test render, which let me finish.