Abstract: A MACHINERY MAINTENANCE WORKER WAS USING A 6-FOOT STEEL RULE TO MEASURE THE INSIDE WIDTH OF AN OPEN ELECTRICAL CABINET. THE SWITCHGEAR CABINET CONTROLLED TWO WEINGARTEN SCREW PRESSES (MODEL 560). HE HAD OPENED (BUT HAD NOT LOCKED OR TAGGED) THE 480-VOLT CIRCUIT BREAKER SUPPLYING THE CONTROLS WITHIN THE CABINET, BUT HE HAD NOT DEENERGIZED THE THREE 1000-VOLT, 800-AMPERE MAIN BUSES WITHIN THE CABINET. THE STEEL RULE CONTACTED ONE OF THESE BUSES AND CAUSED AN ELECTRICAL FAULT. THE RESULTING ELECTRIC ARC BURNED THE EMPLOYEE. HE SUFFERED THIRD DEGREE BURNS OVER 70 PERCENT OF HIS BODY. HE DIED OF HIS INJURIES.