This is crazy.
SBG2 was HUGE and if this isn't a translation error on the part of Octave (which I could understand given the stress and ESL) I have a hard time fathoming what kind of fire could destroy a whole facility with nearly 1000 racks of equipment spread out across separated halls.
I'm really hoping "destroyed" here means "we lost all power and network core and there's smoke/fire/physical damage to SOME of that"
I can't even fathom a worst-case scenario of a transformer explosion (which does occur and I've seen the aftermath of) having this big of an impact. Datacenters are built to contain and mitigate these kinds of issues. Fire breaks, dry-pipe sprinkler systems and fire-extinguishing gas systems are all designed to prevent a fire from becoming large-scale.
Really glad nobody was hurt. OVH is gonna have a bad time cleaning all this up.