On August 3, 2015, an 18-year old truck driver (seasonal associate) with 9 weeks experience was killed at a granite mine. The victim backed his truck under a conveyor belt to be loaded. After exiting the truck, the victim entered a door leading underneath the “sand fines silo.” Soon after entering the silo, the structure collapsed burying the victim beneath the falling material.
Best Practices
- Routinely examine metal structures for indications of weakened structural soundness (corrosion, fatigue cracks, bent/buckling beams, braces or columns, loose/missing connectors, broken welds, spills of stored solids, etc.).
- Periodic detailed inspections should be performed which examine hopper and wall thicknesses, critical connections such as the hopper to the wall, and the material flow conditions. Both the inside and outside of the structure should be evaluated.
- Report any changes in the discharge flow pattern which may be a result of an internal obstruction that causes non-uniform pressures on the silo structure.
- Report all areas where indications of structural weakness are found.
- Schedule inspections of the silo’s interior surface only when all material has been removed to determine if it has become polished and worn from use.
Click here for: MSHA Preliminary Report (pdf), MSHA Investigation Report (pdf), Overview (pdf).