Much of America was stunned into mourning on February 1, 2003 as the space shuttle Columbia was reported to have broken up over Texas. The ensuing investigation revealed that debris at liftoff was the cause of the crash, but the official report suggested that NASA's organizational communication was just as much to blame. This article uses transactive memory theory to argue that there were significant gaps in the knowledge network of NASA organizational members, and those gaps impeded information flow regarding potential disaster. E-mails to and from NASA employees were examined (the “To” and “From” fields) to map a network of communication related to Columbia's damage and risk. Although NASA personnel were connected with each other in this incident-based network, the right information did not get to the people who needed it. The article concludes with extensions of theory and practical implications for organizations, including NASA.