Abstract: Employees #1 and #2 and a coworker were 1 1/2 in. using fire hoses to wash wet sawdust out of a sawdust storage silo after a fire. They used a 1 1/2 in. hose High pressure streams of water were aimed through access doors at various levels in the silo to knock the wet, compacted sawdust down into the middle of the building. A 4 in. hose was then used to flush the sawdust out of an access door at floor level. When the positions of the upper water streams were no longer effective, Employees #1 and #2 entered the silo. The coworker remained outside to act as an attendant. They continued to wash the sawdust out of the silo from their interior, floor-level positions. The wet sawdust remained piled up along the inner sides of the silo above them. Employee #2 aimed at sawdust above their heads and dislodged a compacted block, causing a large amount of flowing sawdust to fall. Employees #1 and #2 were struck by compacted sawdust, knocked down, and engulfed in flowing sawdust. Employee #1 was temporarily buried approximately 2 ft under the surface and suffered life-threatening injuries. Employee #2 sustained multiple contusions and abrasions. The sawdust storage silo was designated as a permit-required confined space, but neither the employees nor their supervisor followed company procedures during this cleaning operation. Provisions for an entry permit, qualified personnel, sawdust removal procedures, retrieval equipment, and rescue services were not followed.