Worker fatally injured after truck rolled down steep slope
Date of incident: May 2013
Notice of incident number: 2013166950138
Employer: Fire-fighting services firm
Incident summary
The driver of a water truck was backing up along a forest service road when the front tire on the passenger side of the truck went over the road’s edge. Two co-workers saw the front tire go over the road’s edge and went to assist the driver. As the driver attempted to drive forward to get the tire back onto the road surface, the rear wheels moved closer to the edge of the road, and at the same time water sloshed inside the tank. The truck tipped off the road, rolling about 100 metres down a slope before striking a tree. The driver was ejected from the truck, and was located further down the slope. He died from his injuries.
Investigation conclusions
Cause- Water truck lost stability and rolled down steep slope: The front passenger tire of the water truck went off the forest service road. While the driver was trying to get the tire back onto the road, the truck lost stability and rolled down the steep mountainside.
- Unsafe decision to travel in reverse: The driver of the water truck made an unsafe decision to travel in reverse in order to refill a water tank that was located a short distance away.
- Effect of water sloshing inside the tank: Water inside a vehicle-mounted container will slosh back and forth during braking and acceleration, generating momentum. The water truck had a high centre of gravity to begin with, and when the water sloshed inside the partially filled tank the truck quickly lost stability.
- Inadequate information, instruction, and training: The driver did not receive adequate information, instruction, and training on the safe operation of the water truck, which was used for delivering water for fire suppression, on the high-traffic forest service road.