Abstract: ON OCTOBER 10, 1984, AT APPROXIMATELY 10:30 PM, EMPLOYEE #1 ENTERED A TANK WHICH HAD CONTAINED CHICKEN BLOOD. THE TANK WAS LOCATED ON THE SECOND FLOOR AND WAS PART OF A CHICKEN PROCESSING OPERATION AT A RENDERING PLANT. THE INSIDE OF THE TANK MEASURED 8 FEET HIGH BY 6 1/2 FEET IN DIAMETER. THE BOTTOM OF THE TANK WAS CONE-SHAPED AND SLOPED OUTWARD AT A 120-DEGREE ANGLE. THE TOP OF THE TANK WAS COVERED WITH LOOSE PLATE STEEL, ONE-THIRD OF WHICH HAD BEEN REMOVED JUST PRIOR TO EMPLOYEE #1'S ENTRY. EMPLOYEE #1 WAS TO ENTER THE TANK TO REPAIR A HOLE IN THE BOTTOM. THE ONLY WITNESSES TO THIS OPERATION WERE TWO OTHER EMPLOYEES WHO OBSERVED FROM OUTSIDE THE TANK. TO GET INSIDE, EMPLOYEE #1 USED A FIXED METAL LADDER AND PLATFORM ON THE OUTSIDE AND A WOODEN LADDER ON THE INSIDE. UPON ENTERING THE TANK, EMPLOYEE #1 WAS IMMEDIATELY OVERCOME BY A GASEOUS, OXYGEN-DEFICIENT ATMOSPHERE. WHEN HE TRIED TO CLIMB OUT, HE FELL BACKWARD INTO THE TANK AND APPARENTLY LOST CONSCIOUSNESS. LOCAL AUTHORITIES WERE UNABLE TO REVIVE HIM. THE GAS PRESENT IN THE TANK WAS IDENTIFIED AS METHANE.