1. A cellular communication network based emergency response system, comprising: a. a mobile switching center (MSC) of a cellular communication network that maintains, in an home location record (HLR) database, in addition to identification of cell towers, a GPS location data of a mobile cell phone device, for devices that are operating in the network; b. the MSC has an interface to an emergency response (ER) system; c. the MSC for a received 911 emergency call from a wireless device retrieves the device's GPS location data from the HLR database and sends to the ER system over the interface.