THE STATISTICS WERE OBTAINED FROM A SURVEY OF ALL 717 SCHOOLS IN SURBURBAN COOK COUNTY, CHICAGO, ILLINOIS. TOTAL SUBURBAN PUBLIC SCHOOL FOR THE 1973-74 SCHOOL YEAR WAS 462,341. FOR THIS ONE YEAR, THE COST OF VANDALISM TO THE COUNTY WAS $1,340,822. THIS INCLUDED VANDALISM OCCURRING INSIDE AND OUTSIDE SCHOOL BUILDINGS AS WELL AS MONEY LOST TO EXPLOSIONS, FIRES, AND OTHER SUCH HAZARDS. INTERNAL DAMAGE OCCURRED TO LIBRARIES, LEARNING RESOURCE CENTERS, WALLS, CAFETERIAS, EQUIPMENT, WASHROOMS, LOCKERS, FURNITURE, WINDOWS, BOOKSTORES, AND STOREROOMS. EXTERNAL VANDALISM INCLUDED DEFACING OF OUTSIDE WALLS, AND DAMAGE TO WINDOWS, GROUNDS AND LANDSCAPING AS WELL AS PLAYGROUND EQUIPMENT, SCHOOL BUSES, AND OUTSIDE SCHOOL LIGHTING. 75 PERCENT OF THE VANDALISM OCCURRED AFTER SCHOOL HOURS COMPARED TO 22 PERCENT DURING SCHOOL HOURS WHEN THERE WAS ADEQUATE SUPERVISION OF THE BUILDINGS. ONLY 23 PERCENT OF VANDALS WERE APPREHENDED BY SCHOOL AUTHORITIES AND 34 PERCENT OF THAT NUMBER WERE REFERRED TO THE POLICE. DURING SCHOOL HOURS, 113 SCHOOLS EMPLOYED 233 SECURITY PERSONNEL. HOWEVER, ONLY 27 PERCENT OF THE SCHOOLS HAD A MECHANICAL OR ELECTRONIC BURGLARY PROTECTION SYSTEM. MOREOVER, ONLY 16.5 PERCENT HAD SECURITY PATROLS WORKING FROM SCHOOL CLOSING TO SCHOOL OPENING. APPROXIMATE COSTS TO SCHOOL DISTRICTS FOR ALL VANDALISM ARE GIVEN. EXTENSIVE TABULAR DATA ARE INCLUDED. (MJW)