JURISDICTIONAL PROBLEMS AND TECHNOLOGICAL LIMITATIONS PREVENTED PREVIOUS IMPLEMENTATION OF THE 911 UNIVERSAL EMERGENCY NUMBER SYSTEM IN ST. LOUIS AND ST. LOUIS COUNTY, MO. AN EXPANDED 911 SYSTEM PROVIDES SOME DISTINCT ADVANTAGES OVER CONVENTIONAL EMERGENCY COMMUNICATION SYSTEMS AND OVER THE EARLIER 911 SYSTEM. SELECTIVE ROUTING, PERFORMED BY A COMPUTER IN THE TELEPHONE CENTRAL OFFICE, DIRECTS EMERGENCY CALLS TO THE CORRECT PRIMARY ANSWERING POINT. AUTOMATIC CALL TRANSFER ALLOWS THE ANSWERING ATTENDANT TO EASILY FORWARD THE CALL TO THE PROPER AGENCY. VISUAL DISPLAY OF THE CALLER'S TELEPHONE NUMBER AT THE ANSWERING CENTER ENABLES THE ATTENDANT TO CALL BACK IF THE CALLER BECOMES INCOHERENT OR HANGS UP BEFORE SUFFICIENT INFORMATION IS GIVEN; IT CAN ALSO DETER PRANK CALLS. THE 911 ATTENDANT CAN COORDINATE AID WITH SPEED AND EFFICIENCY WHEN MORE THAN ONE EMERGENCY SERVICE IS NEEDED. THE COMPUTERIZED 911 SYSTEM IMPROVES DATA COLLECTION REGARDING EMERGENCY CALLING AND PLANNING FUTURE EMERGENCY SERVICES. MOREOVER, IMPLEMENTING 911 ALLOWS STUDY AND IMPROVEMENT OF CURRENT EMERGENCY PRACTICES. COST IS TO BE SHARED BY THE UTILITY AND LOCAL GOVERNMENTS. CHARTS AND ILLUSTRATIONS ARE APPENDED. (AUTHOR ABSTRACT MODIFIED)