The present Reverse 911 Alarm System implements a central alarm distribution site that is capable of generating an alarm indication to warn individuals of a hazard and propagating the alarm indication to selected ones of a plurality of alarm systems that are located in the service area of the central alarm distribution site to warn individuals of a hazard as well as transmitting the alarm indication to individuals via their wireless subscriber devices by the use of wireless multicasting in the wireless communication network that serves the service area of the central alarm distribution site. The central alarm distribution site creates an integrated Reverse 911 system which dynamically selects the alarm systems and the wireless coverage area to encompass the present extent of the hazard and can provide advanced warning to individuals located in an area that extends beyond the present hazard extent area.