Both main and auxiliary backup generators in NYU Langone Medical Center failed during Sandy storm. Apparently, the secondary backup generator is on a low floor and was disabled by the flooding. The primary one is on the roof but the fuel pump is on a lower floor and was flooded. They had to evacuate 200 patients including 20 newborns in ICU. Source: http://www.cbsnews.com/8301-505263_162-57542362/inside-nyc-hospitals-near-disaster-amid-sandy/ . Obviously, they did not design the emergency power system failproof.