Abstract: At approximately 10:00 a.m. on February 21, 2013, Employee #1, a 52-year-old male shipping operator with U S Borax Inc., a surface mining and refining of Borates Company and was working at a shipping dock that contained eight truck bays. Employee #1 secured a load in bay number seven with a load bar, and then walked to bay number six to return an extension pipe. On his way back to bay number seven Employee #1 tripped on an approximately 3 in. change in elevation in the concrete floor, fell, and broke his left femur. The "step" was in a 36 in. wide space between a support beam and a portable dock net support. It was common for the shipping workers to walk in this space when moving between bays. Bays number seven and bay number eight were added years earlier, and this was the reason for this single change in elevation between bay's number six and number seven. The other identical areas between docks are smooth. The cause of this incident was the stumbling hazard created by the 3 in. change in elevation in a commonly used walkway.