IN EVERY INCENDIARY INCIDENT WHERE THE SOURCE OF IGNITION WAS IDENTIFIED, IT WAS EITHER A MATCH, SMOKING MATERIALS, OR A CIGARETTE LIGHTER. IGNITED MATERIALS WERE PRIMARILY MATTRESSES, BED CLOTHES, OR PERSONAL CLOTHING. THE TYPICAL PENAL INSTITUTION FIRE IS AN INCENDIARY FIRE, SET IN A CELL AND PRINCIPALLY INVOLVING BUILDING CONTENTS RATHER THAN STRUCTURAL MATERIALS. IN GENERAL, SUCH FIRES GENERATE INTENSE HEAT AND DENSE SMOKE IN CORRIDORS AND ADJOINING AREAS WHICH HINDER EVACUATION OF OCCUPANTS. PREDOMINANT MOTIVES REPORTED IN PENAL INSTITUTION FIRES INCLUDE INCREASED OPPORTUNITY TO ESCAPE, MALICIOUS DAMAGE, SHOW OF FORCE DURING RIOT, AND SUICIDE. THE HIGH LEVEL OF SUPERVISION AND MASSIVE CONSTRUCTION REPRESENT TWO ARSON-DETERRENT FACTORS OF PENAL INSTITUTIONS. HOWEVER, IN THE INCIDENTS STUDIED A NUMBER OF FIRE PREVENTION AND PROTECTION DEFICIENCIES WERE NOTED, INCLUDING INADEQUATE EMERGENCY PREPLANNING AND TRAINING, INADEQUATE, IMPROPERLY USED, POORLY PLACED, OR UNAVAILABLE FIRE SUPRESSION EQUIPMENT, DELAYED DETECTION TIME, INADEQUATE VENTILATION AND BREATHING APPARATUS UNITS AND EMERGENCY EXITS, LACK OF HEAT/SMOKE PARTITIONS, AND THE BURNING QUALITIES OF BUILDING CONTENTS, PARTICULARLY SYNTHETIC MATERIALS. SUMMARIES OF 19 INCENDIARY INCIDENTS AT CORRECTIONAL FACILITIES/INSTITUTIONS ARE PROVIDED TO ILLUSTRATE A VARIETY OF THESE PROBLEMS AND DEFICIENCIES. PHOTOGRAPHS AND FLOOR PLANS ACCOMPANY THE TEXT. ALSO INCLUDED ARE EXTENSIVE STATISTICAL DATA. (JAP)