Abstract: On March 13, 2013, Employee #1, a heavy equipment operator employed by a large pipeline installation contractor, was operating an ABI Vibrating Hammer at a pipeline construction project. He was driving in piles and removing piles used to hold up shoring during a large excavation. As he removed one pile, the chain broke, and the pile fell. The pile landed on the edge of the ABI machine, injuring Employee #1. He was transported to the hospital, admitted, and treated for multiple fractures and a concussion. He required hospitalization for four days. This event was reported to Cal/OSHA on March 13, 2013 by both the employer and the local fire department. The subsequent investigation revealed that Employee #1 was an experienced ABI Vibrating Hammer operator, having worked for the employer in this capacity for 5.5 years.