Abstract: At 11:30 a.m. on August 14, 1998, an accident occurred at a concrete manufacturing and distribution facility. Employee #1, a maintenance mechanic, suffered a jaw fracture while inspecting silo chutes without deenergizing the turn head above them. Employee #1 was the only yard man at the facility, in charge of all equipment maintenance. He had been working in this field for slightly over one year, having had no previous maintenance experience. Employee #1 was sent by his supervisor to find a possible gravel leak atop the silos, at the filler chutes. A turn-head, capable of revolving in either direction, delivers various gravel grades down four chutes. The main power switch for the turn-head had been installed adjacent to the point of operation for about three months, and had previously been used once by Employee #1. During all other cleaning and maintenance the power had been disconnected by the supervisor from the control room. On the day of the accident, Employee #1 attempted to quickly peek inside one chute without locking-out power, as previously instructed by management. Lock-out was only to be implemented during maintenance and cleaning. While Employee #1's head was at the top of chute #3, the turn-head moved clockwise from chute #2, squeezing Employee #1's head against chute #4. Employee #1 was immediately approached by the supervisor, and transported by Paramedics to White Memorial Hospital, where he was hospitalized and received surgery to the fractured mandible.