The incident occurred on December 13 2016 within the coal lease on an area near the coal handling preparation plant.
Norman, who worked for transport contractor RW & LM Simmons, was given first aid and transported by rescue helicopter to hospital. He died on 15 December 2016.
At the start of shift, Simmons workers discussed cleaning out the trailers at the mine wash bay.
When a truck arrived at the wash bay, Norman directed the truck to the park-up area.
At the park-up area, Norman had a pipe with a fork at one end and a shovel in his hands.
Norman told other Simmons' workers he had to get inside the trailer and dig the coal out.
One worker protested but Norman dismissed him and stated he was not allowed to do it at the wash bay anymore. There was no risk assessment undertaken nor were the hazards discussed.
Norman and two other workers manually cleaned out a coal haulage trailer between 7.10am and 7.50am.
The method the three workers used to access the trailer involved Norman prying open the tailgate at the rear of the trailer while the other two workers lifted and held up the tailgate.
This allowed Norman to prop open the tailgate with the handmade tool.
Norman then entered the trailer through the open tailgate and used a shovel to clean away the coal residue that had built up in the trailer.
Norman then exited the trailer without incident and removed the handmade tool that was used as a prop.
Norman and two other workers attempted to manually clean out another coal haulage trailer using the same method between 9.00am and 9.30am.
However, Norman had trouble getting the prop in place while the tailgate was being held open by two co-workers. The tailgate fell and crushed Norman's head between the tailgate and the rear of the trailer body causing serious head injuries.