been in the network/computer biz for over 20 years. I doubt this rumor is true. prolly some partial truth to it.. prolly is a switch there. chillers empty.. i would expect the power to go out first. i've seen both happen btw. most places like this have multiple backup.. batteries, dual generators. the generators either run on diesel or natural gas. in the first case they run out of diesel after a few days, in the second case they run out as soon as the gas lines are cut. the chiller thing is something they almost never think of. water gets cut and a place useing water chillers for chilling computer rooms with air conditioners those rooms heat up and the gear fries. i saw this happen once almost at a company i worked for. at the last minute pump truck arrived, filled up a t a local creek and pumped the water 3 or 4 stories up to the cooling tower.
there was a story going around amongst the internet infrastructure network people after 911 that there was an ATT colo (co-locate) under the twin towers that was complete buried and unaccessable but continued to function for a couple of months routing internet stuff and so forth. this was a urban legend basically and so is this about SBC.