Social media has become a critical source of information for the public, government authorities, and other stakeholders both during and after large-scale emergencies. However, the sheer volume of data and the low signal-To-noise ratio, with respect to information, limit the effectiveness and the efficiency of using social media as an intelligence resource. In this paper, we describe Australian Crisis Tracker (ACT), a tool designed to facilitate the understanding of critical information available in social media channels for people and agencies responding to natural disasters. ACT harnesses the Twitter streaming application program interface by processing each tweet through a pipeline of analytic components, including filtering, metadata parsing, image extraction, and clustering of relevant tweets into events. Each of these events is then geocoded, categorized, and augmented with images from Instagram. The pipeline of these analytics is coupled to a web-user interface that allows stakeholders to better access information during natural disasters. In this paper, we describe the ACT pipeline, analytics, and pilot by the Australian Red Cross during the 2013-2014 Australian bushfire season.