What's the legal justification behind doing this? Not surprised that it's done, but am surprised that there's a legal mechanism in place to shut down cell service for an entire major metropolitan city.
I believe that in an emergency the FCC reserves the right to shutdown whatever it sees fit. (Something like this was reported on Bloomberg news when AP first reported it.)
I'd hope (assume, really) that calls to emergency services can still go through.
I do believe public emergency transponders and radios use a different spectrum (independent of the spectrum used by the general public for cell phone calls, etc), but am unsure if that's still the case for making a 911 call. I don't believe it is... Thus, if cell towers are disabled, and hence, your phone doesn't work -> you won't be able to make emergency calls. Someone please correct me as I don't want this to be true.