Starting at 8:05 a.m. on Friday, Oct. 26, New York City communicated to residents through its official Twitter feed about Hurricane Sandy's arrival -- which wreaked havoc on the entire subway system, "in every borough and county of the region," said MTA Chairman Joseph Lhota in a statement, adding that the storm ripped out power and inundated tunnels, rail yards and bus depots.

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.

Jessica Mulholland, Web Editor Jessica Mulholland  |  Web Editor/Photographer

Jessica Mulholland has been a writer and editor for more than 10 years. She was previously the editor of Emergency Management magazine, and she loves that she can incorporate her love of photography into her work as a part of the Government Technology editorial team. Jessica can be reached at jmulholland@govtech.com and @jbronwen on Twitter.