Abstract: At 9:30 a.m. on September 5, 2017, Employee #1 had been instructed to add a mid-rail to the existing guardrail that was on the mezzanine level above the machine shop. The mezzanine already had a top rail and an opening in the center where the employee could gain access to the mezzanine. Employee #1 placed a metal mobile ladder stand with 8 steps in front of the opening to try to access the mezzanine level. The top platform level of the metal mobile ladder stand was too low to access the mezzanine, so the employee put a plank across the two mid-rails at the top of the metal mobile ladder stand in order to gain additional height to step up onto the mezzanine level. Employee #1 was standing on the plank that he had placed between the mid-rails of the mobile ladder stand when he lost his balance and fell approximately nine feet, hitting and sliding down the eight steps of the metal mobile ladder stand and landing on the concrete below. The employee sustained a head injury, with loss of consciousness, and a fractured shoulder. He was admitted to a local hospital for treatment.