The 20-year-old miner who died after a mishap at the Wolverine Mine last month was struck from behind by the vehicle he'd left parked on the down ramp.

A preliminary report released Wednesday by the Yukon Workers' Compensation Health and Safety Board indicates Paul Wentzell was driving down into the mine, located 180 kilometres southeast of Ross River.

He stopped because a piece of heavy equipment was parked on the slope ahead of him.

Wentzell parked his 2004 Toyota Land Cruiser pickup on the 15 per cent grade. He placed the vehicle in neutral, engaged the emergency brake, and began walking toward the tractor some 20 metres away.

When the emergency brake failed, the truck rolled down the ramp and struck Wentzell from behind, knocking him to the side and causing internal injuries.

The truck continued on until it struck the piece of equipment.

Wentzell, a Newfoundlander who was living in Alberta, was walking and talking after the incident, but was immediately flown to Whitehorse on a regular crew-change flight to be examined at Whitehorse General Hospital.

The mishap occurred at approximately 9 a.m. on Oct. 19. He arrived at the hospital at 12:20 p.m. but died 48 minutes later, at 1:08.

"Preliminary findings indicate that the direct causes of this fatality are a result of the vehicle being parked in neutral on a 15 per cent slope and relying on an emergency brake that was unable to hold it in place,” reads the report from the compensation board.

"The vehicle rolled down the slope, striking the worker and causing internal injuries serious enough to result in the worker's death.”

The report says the regular underground procedure for parking a vehicle with a standard transmission on a slope is to turn off the vehicle, put it in gear and engage both the emergency brake and parking brake.

Ideally, the wheels would be chocked with wedges or rocks for added security, the report adds.

Wentzell did not turn off the vehicle, nor did he engage the parking brake.

Underground mining standards require that a slope is no steeper than 16 per cent. By comparison, the steepest sections of Two Mile Hill and Robert Service Way are 10 per cent.

Kurt Dieckmann, the board's director of occupational health and safety, said in an interview Wednesday the matter is still under investigation. Officials want to determine what safety procedures were in place, and to what extent Wentzell was familiar with those procedures.

Investigators are also continuing the investigation into the failure of the emergency brake, and are checking into what changes, if any, the company has made since the fatal mishap, he said.

Dieckmann said an emergency brake for underground vehicles is designed to clamp around the drive shaft and lock it in place to immobilize the vehicle.

The compensation board, he said, decided to release the preliminary reports on the Wolverine incident and a placer mining death outside Dawson City in September as education tools to raise awareness and help prevent similar accidents.

Wentzell was working for Procon Mining and Tunnelling Ltd., a national company with long-standing underground mining experience.

Procon is under contract with the Chinese-owned Yukon Zinc Corp. to complete the necessary underground work to get the mine ready for production next spring.