Abstract: At 3:35 p.m. on December 27, 2022, an employee was knocking gypsum dust off the interior walls of the end saw baghouse hopper. The baghouse was a large steel structure, 40 feet in height, with inward converging walls that led to two screw augers that moved gypsum dust to the center of the hopper. The dust would then fall through a central rotary valve and be moved back into the facility. The hopper was equipped with vibrators on the exterior siding and pneumatic "poppers" amongst the filter bags to prevent dust build-up. However, when additional moisture was added to the dust, it stuck together. The employer implemented a procedure of deactivating all powered equipment and opening the main hatch to knock the dust down using a stick or a pneumatic air wand. Also, employees could open the two hatches under the auger and use the same method to knock the dust from the bottom of the hopper. Employees were not instructed to climb into the hopper. The employee was providing a tour to a new coworker when the senior supervisor asked him to knock some of the dust off of the inner walls. The employee went to the main hatch and began to knock the dust out of the hopper using a long stick. The coworker was cleaning dust at the bottom of the stairs when the employee said he was going inside. The employee climbed into the hopper then called out to the coworker to get him a light. The coworker found a flashlight and was climbing up the stairs when the dust shifted and fell, blocking the main hatch. The coworker cleared away dust from the hatch but could not see the employee so he called for another coworker to get help. The employer initiated a rescue operation and notified emergency services. Once sufficient dust was removed from the hatch to allow entry, the senior supervisor entered the space and was able to find the employee's hand and his unresponsive body. The employee's body was removed by the fire department through an opening cut into the side of the hopper.