Abstract: On November 12, 1999, Employee #1, of Matson Sand Island Marine Terminal, was trying to couple a Sisu Hustler marine terminal tractor, serial #72EA099AD384, Matson ID #1679, to a Wabash flatbed trailer, serial #1JJF40278RLl210566, loaded with two flat tracks. Employee #1 had been assigned to move the trailer from Stall #27 to the container freight station. No one observed the incident, but he apparently was coupling the tractor to the trailer when he missed the kingpin. The fifth wheel of the tractor was behind the kingpin. Employee #1 was trying to free the fifth wheel from under the kingpin when he became pinned. He died of traumatic asphyxia secondary to being pinned between the cab of the tractor and the trailer. The first coworker on the scene stated that the gear stick was in reverse and the parking break had not been set. Regulations that may have prevented this accident include T8CCR 1917.44 (J): vehicle was left unattended with its engine running and without being secured against movement. This regulation does not have a training requirement. There were no industry-wide procedures in place for coupling and uncoupling. Five operating manuals, the Pacific Maritime Association, and the teamsters union all have similar, but different, steps to do the task. None address how to handle instances where the kingpin is caught behind the fifth wheel.