Abstract: TWO EMPLOYEES WERE WORKING UNDER A SEMI-TRAILER TO REPAIR THE AIR VALVE FOR THE BRAKE SYSTEM. ONE OF THEM WAS USING A 7/8-INCH COMBINATION WRENCH TO REMOVE THE AIR VALVE FROM THE CYLINDER. A TWO-WIRE TROUBLE LIGHT WAS DRAPED OVER THE CYLINDER AND BECAME PINCHED BETWEEN THE WRENCH AND THE FRAME OF THE TRAILER AS THE VALVE LOOSENED SUDDENLY. THIS EMPLOYEE RECEIVED AN ELECTRIC SHOCK AS A RESULT AND COULD NOT RELEASE HIS GRIP ON THE WRENCH. THE OTHER EMPLOYEE CLIMBED OUT FROM UNDER THE TRAILER, TOUCHED THE METAL TRAILER FRAME, AND ALSO RECEIVED A MILD SHOCK. THE SECOND EMPLOYEE DISCONNECTED THE TROUBLE LIGHT AND PULLED THE FIRST EMPLOYEE OUT FROM UNDER THE TRAILER. CARDIO-PULMONARY RESUSCITATION WAS ADMINISTERED TO THE FIRST EMPLOYEE, AS HIS BREATHING HAD EVENTUALLY STOPPED. BOTH EMPLOYEES SURVIVED.