As a country that frequently experiences natural calamities, one important issue in the Philippines is disaster management. In the past years, there has been a growth in the number of literature in an area of research that focuses on the role of communication, particularly social media, amidst a crisis. This paper offers a preliminary study on crisis communications in Twitter, one of the leading social networking sites, during Typhoon Ulysses (Vamco). Through a content analysis of the tweets, the characteristics of users and types of information involved in crisis communications are identified. Using the Four Channel Model of Communication, the study identifies the prevailing dynamic of communication among the actors in a crisis event. The results of the study show that individuals (i.e., ordinary citizens) became very active in disseminating information about the coordination of relief activities. In the end, the paper stresses the usefulness of social media for disaster management and the obstacles to the use of its full potential.