On September 15, 2010, the TBM involved in the incident had been hydraulically pressurized to ensure its components and functions were working properly. The TBM contained a safety device called an accumulator, which remains pressurized even when the rest of the machine is not pressurized or otherwise operational. The accumulator must be depressurized separately prior to its disassembly. That afternoon, the company failed to confirm that the accumulator had been depressurized, as that person responsible for this task had been directed to help with other work.
Later in the evening, a worker was directed by a supervisor to help two other workers to disassemble and prepare the TBM for shipment. When the crew unscrewed a hydraulic hose that was connected to the accumulator, a jet of hydraulic oil hit the worker in the face and neck. The worker then fell and suffered head injuries.
A Ministry of Labour investigation found that Caterpillar Tunneling Canada Corporation, as an employer, failed to ensure the pressure inside the gas compartment of the accumulator was adjusted to atmospheric pressure before a hydraulic fitting was removed.Caterpillar Tunneling Canada Corporation was fined $130,000 by Justice of the Peace D. Keith Currie. In addition to the fine, the court imposed a 25 percent victim fine surcharge, as required by the Provincial Offences Act. The surcharge is credited to a special provincial government fund to assist victims of crime.