This study investigated Internet communication and use in a crisis situation, Hurricane Katrina, to explore the role of the Internet in supporting or diminishing geographically-based community during a crisis. The researchers conducted an online survey of Internet users (n=1192) from the dispersed metropolitan New Orleans area. The survey focused on amount, type, function, and importance of Internet use to creating and maintaining social capital, supporting geographically-based communities, activating social networks, reducing uncertainty, and achieving both expressive and instrumental communication goals. The results indicated that Internet users in a crisis situation went online to seek interactive fora specific to their neighborhoods and to activate weak ties in their social networks. They engaged in more uncertainty reduction behavior when experiencing higher degrees of damage. They turned to the Internet in place of other media as a result of disruptions caused by the crisis. Women valued online expressive communication more than men did. The findings suggest that social capital theorists would benefit from a communication perspective on the Internet. The study also led to the formation of suggestions for emergency preparedness agencies, shelter providers, crisis victims, and online news providers that can improve emergency response.