Even when you have generators, there are still a myriad of things which can and do go wrong no matter how hard you try, even with trebly redundant backups, etc. etc.
A fuel supplier accidently puts half a load of jet fuel instead of #2 diesel in your storage tank, which you won't find until it reloads the run tank from the day tank.
Run the generator under load periodically. Have your gen maintenance contractor do fuel tests quarterly. Water is just as bad in the Diesel tank.
This can be solved, it's a matter of logistics and procedures, when did you last hear that an airline filled with diesel instead of Jet-A1? -Peter Before anyone statrs to build a very expensive pop, revisit the idea of several locations and geograpghical diversity, as it is close to defend a single locataion, a competing ISP could go around and cut all your wires....