Abstract: AN EMPLOYEE DEENERGIZED AND LOOSENED A 100-AMPERE, THREE-PHASE CIRCUIT BREAKER THAT HAD MALFUNCTIONED. HE STEPPED BACK ABOUT 2 FEET AND TALKED TO TWO OTHER PEOPLE. AFTER ABOUT 2 MINUTES, AN ELECTRICAL EXPLOSION AND FIRE ERUPTED AT THE BOTTOM OF THE PANELBOARD, 16 INCHES FROM THE CIRCUIT BREAKER. EMPLOYEE #1 SUFFERED SECOND AND THIRD DEGREE BURNS OVER 30 PERCENT OF HIS BODY. HE WAS HOSPITALIZED FOR 30 HOURS. EMPLOYEE #2 SUFFERED SMOKE INHALATION FIGHTING THE ENSUING FIRE. EMPLOYEE #3 SUFFERED MINOR FLASH BURNS AND SMOKE INHALATION. EMPLOYEES #2 AND #3 WERE TREATED AT A HOSPITAL AND RELEASED. EMPLOYEE #4 SUFFERED MINOR FLASH BURNS. SHE WAS TREATED AT THE SCENE AND RELEASED.