An emergency response computer system is used in operative communication with mobile computing devices for a set of device users to automatically coordinate emergency responders. The system can produce a report for emergency responders that identifies the locations of mobile computing devices, and the report can be helpful in identifying the locations of people and evacuating them when there is a mass emergency. The system can evaluate the content of emergency messages as well as proximity of the locations of the mobile computing devices that sent the emergency messages and the timing of the emergency messages to determine whether a mass emergency event is occurring and the appropriate level and type of emergency responders (police, fire, and/or medical). The system can identify and connect with video cameras throughout the geographic area that is covered by the system's emergency responders.