The pilot's loss of consciousness while taxiing due to an accumulation of toxic levels of carbon dioxide gas inside the airplane as a result of dry ice sublimation. Also causal was the pilot's decision to fly the airplane in an unventilated configuration, the operator's policy that allowed this configuration, and the shipping company's inadvertent loading of excess dry ice, which exacerbated the concentration of carbon dioxide.

The inattention of the driver of a service truck to yield to aircraft and subsequent collision with the airplane as it crossed the service roadway.