Abstract: ON JUNE 21, 1990, EMPLOYEE #1, A BAG HOUSE SUPERVISOR, AND EMPLOYEE #2, A PLANT ENGINEER, WITNESSED PAINT PEELING OFF THE LOWER PART OF THE HOPPER OF THEIR NEWLY-INSTALLED ALUMINUM DUST COLLECTION SYSTEM. BOTH HAD RECENTLY ATTENDED A TRAINING COURSE REGARDING THIS SYSTEM AND RECOGNIZED THIS AS AN INDICATION THAT THE DUST WAS ON FIRE. THE MAINTENANCE SUPERVISOR WAS NOTIFIED, AND THE SYSTEM WAS CLOSED OFF AND THE DAMPERS WERE SHUT SO THAT THE FIRE WOULD BE SMOTHERED FROM A LACK OF OXYGEN. THE FIRE APPEARED TO HAVE GONE OUT. THE TWO EMPLOYEES WENT OVER TO THE HOPPER AND WERE STANDING UNDER IT WHEN AN EXPLOSION OCCURRED, POURING HOT DUST OVER THEM. THE TWO EMPLOYEES WERE HOSPITALIZED AND DIED A FEW MONTHS AFTER THE ACCIDENT. EMPLOYEE #1 DIED ON JULY 26, 1990, AND EMPLOYEE #2 DIED ON SEPTEMBER 14, 1990.