The goal of this study is to understand the potential benefits and drawbacks of using Information Communication Technology (ICT) systems to communicate emergency reports and DRR information. The study focuses on a particular application, AtmaGo, which was launched in Indonesia in 2015. Developed with the concept of crowdsourcing, AtmaGo enables its users to share real-time disaster-related information, as well as to spread DRR information, such as how to prepare for and prevent disasters. Particularly in the Jakarta area, AtmaGo also provides alerts from government sources directly to users. This study aims to better estimate the potential impact of AtmaGo in improving disaster preparedness and response in Indonesia. The researchers surveyed users and non-users of AtmaGo in five neighborhoods in the Greater Jakarta area with the intent of understanding: 1) how people get emergency warnings and DRR information, 2) whether AtmaGo can provide these warnings in an actionable way, and 3) the potential benefits of successful warning systems in terms of avoided damages as well as the prevention of mortality and morbidity. This research resulted in nine main findings: 1. There is a growing usage of social media platforms like AtmaGo as a source of disaster information and alert. 2. Emergency alerts and related DRR information can help users take effective preventive actions: 30% of AtmaGo users who receive warnings take preventative action, such as moving valuables, warning neighbors or evacuating. 3. Based on the survey, AtmaGo emergency alerts can reduce property damage caused by floods and other disasters by $324 per household per year for residents of the Jakarta region, assuming that effective action can reduce damages by about 50%. 4. If AtmaGo reaches a scale of 5% to 10% of households in the Jakarta area, this would equate to an avoided damage benefit of $53 million to $106 million per year assuming that 30% of users take effective action that reduces damages by about 50%. 5. By improving community response to floods and other emergencies, AtmaGo can also reduce healthcare cost by an average of $14 per household per year for residents of the Jakarta region. 6. If AtmaGo reaches a scale equivalent to 5% to 10% percent of Jakarta’s population, the study estimates that this could reduce healthcare spending by $2.3 million to $4.6 million per year assuming that 30% of users take effective action that reduces damages by about 50%. 7. Among a group of 100,000 healthy people, AtmaGo can save the equivalent of 643 years of life when considering morbidity and mortality caused by floods and other disasters. This metric was measured using Disability Adjusted Life Years (DALYs) while assuming that effective action can reduce impacts by about 50%. 8. AtmaGo also contributes to the improvement of social cohesion, which has been linked to an improved community response to disasters. According to the survey, 79% of users found AtmaGo helpful or very helpful in connecting them with the community. Additionally, 67% of respondents found AtmaGo helpful or very helpful in assisting them to prepare for disasters. 9. Although the researchers acknowledge that not all people who receive an alert will take action, 68% of users reported sharing information they found on AtmaGo with other people and, amongst those who shared, 13% of them proliferated disaster reports. Each user, on average, shared AtmaGo posts with over 28 other people.