Abstract: At approximately 11:00 a.m. on July 5, 1988, Employees #1, #2, and #3 entered a quarry sand bin to clear material that had built up inside and was clogging up the funnel. The bin was cone-shaped measuring 20 to 25 inches high, 12 feet in diameter, and narrowing to approximately 18 inches at the base. Material is dumped in at the top and a sifter allows finely crushed material to funnel out the bottom. Material had built up on the sides as high as the Employees' heads. They apparently entered the bin before scraping down this material and when the material broke loose, Employees #1 and #2 were completely engulfed and subsequently asphyxiated. Employee #3 apparently jumped in to try to save them and was buried up to his waist, incurring only minor injuries. The main causal factor appears to have been inadequate preparation and use of improper procedures while undertaking this task.