Abstract: On January 26, 2007, Employee #1 was working as a sorter for Madera Disposal Systems, Inc., a solid waste reclamation company, in Chowchilla, CA. He was obtaining a tool from a supervisor, and to do so, he transited an area where another crew was replacing a conveyer's edge guard retaining bolts. The crew had removed two sorting chutes, leaving two unguarded two-foot by three-foot openings in the floor of a five-foot-wide walkway of an elevated sorting platform. Employee #1 stepped into one of the openings and fell sixteen feet to the asphalt floor below. He sustained a head laceration and fractures to his knee and vertebrae, and he was hospitalized for two days. Replacing the edge guard bolts was customarily performed by sorters once a year under the supervision of the floor supervisor. Written procedures were not developed for this operation.