Do I understand it correctly? "This was part of a standard pre-launch static fire to demonstrate the health of the vehicle prior to an eventual launch.". So they set some fire before the launch? Why?
The point of a static fire is to test the launch systems. The hope is that problems can be noticed before the actual launch, where they are more likely to cause catastrophic failure (and where we they might not be noticed in time to abort).
Better to have the rocket explode on the pad in a controlled test than in the air over a populated area.
https://www.reddit.com/r/spacex/comments/4f9fxm/do_other_lau...