Thank you for your service, baker anon.
Ex-IT-fag here.
The way these massive data centers are designed for high availability, with redundant hosts at different sites, diverse multiple routing, fiber channel disk mirroring to an off-site location, redundant/multiple networking infrastructure, load balancing hardware, etc. to my mind it is inconceivable that a fire at one data center disrupts the entire operation. Big companies calculate that they are losing millions of dollars every time their IT infrastructure is down for any length of time.
So there has to be some other explanation.
Maybe it was an attack … perhaps some kind of hacker attack that told their air conditioning unit to catch fire … perhaps a physical attack … but even then it seems quite impossible that a serious outage at one site could take everything down. Unless they were morons when they designed it. But big companies have big IT suppliers advising them and helping make it failure-proof.
I have to assume that the takedown was done purposely by whomever, and a "fire" is just an excuse to explain to the public why their services have failed in such a spectacular way.