EE WAS REPLACING THE TIE ROD INSIDE THE ROLLER MILL. VENTILATION INSIDE THE MILL WAS INDUCED BYTHE NORMAL AIRFLOW SYSTEM. AT A CERTAIN MOMENT ALOW VOLTAGE FAILURE OCCURS CAUSING THE BAGHOUSE VENTILATION FANS TO FAIL AND THE SYSTEM BECOMES POSITIVE CREATING A DENSE CLOUD OF DUST IN THE MILL. AS HE RUSHED OUT OF THE AREA HE TRIPPED & FELL TWISTING HIS LEFT ANKLE & INHALED DUST.