When disasters like Hurricane Sandy happen, and other channels of communication become too slow or too scarce, Twitter can be a terrifically useful source for first-hand information.
So how have people affected by Hurricane Sandy been using Twitter to help each other and share knowledge?
The Lifeline page displays a random tweet that would have been particularly helpful to people living in Sandy's path. What areas are being flooded, and what roads are closed? Where can power be found, and what should people be doing to survive? What can people do to help?
The Photo page displays a random tweet that contains a particularly interesting, informative, or emotional picture relating to the effects of the storm.
Below each tweet is a map that shows how that tweet was shared across the country.
Refresh this page to see another tweet.