Given the news reports and my experience with emergency flares in a process unit, I suspect this was only controlled flares and no fire outside intended release.
An emergency flare from an upset in a process unit can be a massive fire, but completely under control from a nozzle designed for the heat and flow.
Understood, we have a family member who works at the neighboring refinery. The local news report described the fire as an “unplanned fire event,” which is a rather tongue-in-cheek understatement in itself given how there were multiple fires underway for awhile, and they were large enough to tower over the tank farm in at least two locations with what appeared to be other smaller fires in between and around the larger two flames. Two and a half hours later one of the two major sources still flared up from time to time atop or behind one of the storage tanks, while the other fires appeared to have been brought under control and were venting. So, this event appeared to be something considerably more than just some flame and flare from one of the nozzles or vents in a planned unit restart gone awry.