Response of emergency units after natural disasters, such as earthquakes, has to be coordinated, fast and efficient in order to rescue and care for the victims, keeping all the population –and the units themselves– safe amidst the chaos. Outages in mobile networks, as well as fiber- or copper-based landline and Internet connections are to be expected in such situations, so alternative communication solutions must be considered. To contribute in this duty, we propose a communication system that uses the LoRaWAN architecture to allow citizens to report their status to emergency units and public authorities with simple messages and interaction mechanisms. To analyse the system performance and capabilities we model a district of Coquimbo, a harbour town in Chile, that houses approximately 28.000 people in 7.500 homes, and simulate it with a baseline configuration. We explore several modifications of the system in order to determine its characteristics and limitations, to better understand its scalability and portability to other environments, and to outline the remaining challenges to make the system attain to specific performance guarantees