Case Study: In 2016, several workers in Kentucky were laying a sewage pipe in a trench excavation. The trench was just over 12 feet deep, and in order to provide a safe workspace, a trench box was placed inside. However, the trench box measured only 8 feet - 4 feet too short. In addition, the parking lot surrounding the trench already showed signs of distress and previous excavation, and no testing to determine an appropriate protective system was conducted prior to beginning work. Two workers were together in the trench box when a portion of the trench wall collapsed, dropping a large amount of soil and concrete on top of the workers. One worker was completely buried, and his coworker was trapped and immobilized from the waist down. Although coworkers and professional rescue services attempted to extract the workers, the worker who was fully buried was pronounced dead at the scene from asphyxiation and blunt force injuries from the falling material.
Key Takeaway: Protective systems are only effective when they are properly implemented. Trench boxes and shoring should extend at least to the top of the excavation, if not further. In addition, there was no testing done prior to work beginning, and there was no easy means of egress from the trench box. Had the protective systems been measured and constructed correctly for the task at hand, the accident could have been prevented and a life saved.
