Over the last five days, the city has tweeted and retweeted information about evacuations, road and bridge closures, power outages, school closures and blood donations, among many other things, some of which are displayed on the map above (view a larger version here).
Using Twitter during a disaster is becoming much more prevalent, as also illustrated in August 2011 when a magnitude 5.8 earthquake struck central Virginia and was felt from New York City to the Carolinas and west to Ohio.