Abstract: Employee #1 and a coworker, both shippers, were assigned to load trailers with skids of printed catalogs. The approximately 92 1/2 ft wide by 45 ft long trailer was half loaded with approximately 10 skids. Employee #1 went into the trailer with a skid and was placing it into position on the right side when the coworker, operating a new Yale fork transporter, model #MPW-40-SAN-12-C-2748, SEC N-446608, entered the trailer on the right with another skid. The coworker could not see over the load, which measured approximately 60 in. high by 42 1/2 in. wide. He backed into Employee #1, fracturing the employee's left leg in two places below the knee. The coworker was the only witness. Although the employer has a fork truck training program, participation is voluntary. Other causal factors include the fact that the coworker had only informal training despite 4 1/2 years on the job, lack of communication between employees, failure to sound a horn when entering a confined space, haste, and inattention.