The motivation for developing, administering, and participating in full-scale disaster drills is multifold. Emergency drills not only test the capacity of emergency systems but also allow organizations to learn as well as improve processes and communication structures before disasters strike. They have been used as a platform to develop and maintain collaborative networks. This article examines the extent to which organizations collaborate with others during emergency/disaster drills. A social network analysis is employed to determine the patterns of communication and interorganizational networks during the planning and implementation of a full-scale emergency exercise. Specifically, we seek to understand the communication lines that stakeholders used to receive updated information, who they reached out to when standard communication channels were down, and what backup systems were in place. The research was conducted in a municipality located in north central Texas. This study was based on field observations and involved 14 face-to-face interviews with experienced public officials and first responders involved in a municipal government emergency drill/exercise. The interviews were administered after the 2017 full-scale emergency drill. Three major findings can be emphasized from this study. First, two types of organizations, namely, city fire departments and a university partaking in the exercise, played central role as a "bridge" between various organizations during the emergency drill. Second, the types of information considered important during the exercise can be categorized as strategic, procedural, and technical information. Finally, several back-up systems including ham radio, cellphones, internet back-up, and satellite were used to maintain communication channels.