I'm kind of an optimist; I believe it'll only be a matter of hours total outage. The generator is fine, the equipment is fine, the internet connectivity is fine... the only problem is getting fuel up to the generator on the 17th floor, while the fuel pumps in the basement are submerged. Someone will carry it up 17 flights if need be.
Sorry for what you are going through obviously. One thing I have found though in disaster planning is that it pays to be a pessimist. While worrying certainly doesn't help once you have a problem to solve doing so in advance helps you anticipate things that you need to take into consideration when planning.
I feel for the guy/gal/group that draws the short straw and has to tote a 400-ish pound 55 gallon drum of diesel up 17 flights. "Whelp that lasted for 5 minutes, again!" ;)
The datacenter is in Zone A, which did receive the mandatory evacuation order from the city, but we have a few people from Fog Creek onsite or nearby right now and there is at least one person from PEER 1 there right now. Roads to the area are open, life is returning.