Looks like two seperate explosions, the smoke on the left looks to be from a smaller explosion that probably happened first since it seems to be fading.
Something very similar happened in Oct 2010 at another base. Iranians said accident but there was speculation later it was a sabotage and the site was a lot more important than just a ammo dump.
This is probably something similar.
The blast to which you refer was missiles and reports indicated it was fatal, numerous deaths.
I’m hoping it was an IED storage building or factory on the base that blew up in their faces.
I have reservations this was an accident” but no doubt will be reported as such. Seems to me might be “communication” when voices go unheeded.