[LonePalm]

Looks like a BLEVE. The white cloud just before the fireball was the give away.

Here is a compilation of bleves.

WWG1WGA

Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)

[xone]

more likely:

https://www.youtube.com/watch?v=ksOBEKHxe14