ON JANUARY 5, 1975, HOBART, WAS DIVIDED IN TWO WHEN A FREIGHTER COLLIDED WITH THE TASMAN BRIDGE, KNOCKING A SECTION OUT OF IT. THE SUBURBS OF THE EASTERN SHORE, WITH ALMOST NO INDUSTRY OR BUSINESSES OF THEIR OWN, HAD A LARGE LABOR FORCE WHICH WAS CUT OFF FROM ITS PLACES OF WORK. THSES WORKERS WERE ALSO ISOLATED FROM MOST SCHOOLS, HOSPITALS, AND OTHER OFFICES AND SERVICES. CHARACTERISTICS OF THE AREA AND BEHAVIOR PATTERNS BEFORE THE ACCIDENT ARE DISCUSSED TO PROVIDE A BACKGROUND. A SECTION ON DISASTERS AND THEIR EFFECTS COMPARES THE AFTERMATH OF NATURAL AND MORE LOCALIZED DISASTERS -RESCUE PATTERNS, LOOTING PROBLEMS, UTILIZATION OF POLICE -- WITH THAT OF THE HOBART BRIDGE CRISIS. RESEARCH OF THIS DISASTER WAS CONDUCTED TO EXAMINE THE EFFECTS OF PARTIAL ISOLATION, DIFFICULTIES IN COMMUNICATION, CRIME, ECONOMIC STRINGENCY, FAMILY DISRUPTION, AND DEPRIVATION OF AMENITIES ON THE POPULATION OF EACH SIDE OF THE RIVER. AIMS AND ELEMENTS OF THE RESEARCH ARE DEFINED. SUMMARIES OF FINDINGS AND SUPPORTING DATA ARE GIVEN IN THE AREAS OF CRIMINAL PATTERNS AND OFFENSES; ROAD CONDUCT; ESSENTIAL SERVICES, ASSOCIATIONS, AND AMENITIES; AND ECONOMY, INDUSTRY, AND UNEMPLOYMENT. SPECIAL PROBLEMS PRESENTED BY THE DISASTER ARE ANALYZED, INCLUDING CHILDBIRTH, THE AGED, AND ADOLESCENT ACTIVITY. THE VARIED EMOTIONAL RESPONSES TO THE CRISIS, RANGING FROM AGGRESSIVE PROTEST TO APATHY AND DEPRESSION, ARE DISCUSSED, AND THE DATA OBTAINED ON CRIME AND OFFENSES ARE INTERPRETED. CONCLUSIONS DRAWN FROM THIS STUDY ARE SUMMARIZED AS GUIDELINES APPLICABLE TO OTHER EMERGENCIES OF THIS MAGNITUDE. REFERENCES ARE PROVIDED.