Abstract: At approximately 3:55 p.m. on Friday, August 19, 2011, Employee #1, an equipment maintenance worker, was working alone in the maintenance shop removing a hydraulic pump from a Yazoo/Kees Zero Turn commercial lawn mower (total estimated weight of 800 lbs.). The employee had raised the rear of the unit with an automotive hydraulic jack but apparently failed to crib or block the unit to prevent it from falling. The victim was lying on a wheeled "creeper" while working with the upper area of his body under the mower frame. At some point during the operation, the mower sliipped from the jack and the employee's head was caught between the mower frame and the concrete floor. The employee was killed by trauma to the head.