Throughout much of 2001 the Mobilization for Global Justice Coalition (MGJC) planned a series of mass demonstrations targeting the World Bank and International Monetary Fund to occur in Washington, DC in late September. The terrorist attacks of September 11 created a crisis for the 117 social movement organizations (SMO) involved in the broad-based coalition and forced protest leaders to reevaluate their coalition strategy. This analysis chronicles the dissolution of the MGJC and explains the decisions made by SMO leaders to abandon or disband the coalition. By leading their organizations in ways they expected to be perceived as legitimate in the eyes of key allies and supporters, leaders sought to preserve their SMO's core exchange relationships through the 9/11 crisis. At a minimum, leaders sought to insulate their organizations from irreparable harm and position them competitively for the uncertainties of the post-crisis environment. Many organizations made decisions commensurate with homophilous or exemplary organizations in a process resembling "social contagion" while others capitalized on the crisis enhancing their influence. This research relies upon participant observations of pre- and post-9/11 organizing meetings, examination of coalition documents, and interviews with key MGJC leaders.