Comment: What Happened Here - My Semi-Ignorant Theory

Camera was aimed at the plant because it was the most important thing to film during the storm event - that is why it was 'caught on film'.

Initial explosion was either cause of or part of chain-reaction of explosions.

Massive flare-up of fuel consumes all available oxygen - fires extinguish themselves but heat remains.

More oxygen flows in, allowing hot spots to recombust, burn off remaining carbon-based materials in area at more of a campfire pace.

Looks very similar to a classic backdraft scenario, much like mine and my brother's garage fire of '07 which would alternate from slow burn to blowtorch intensity flames then back again every 10-20 seconds.

Not good.