An old logging road on a steep hillside was being reconstructed, and the rock quarry site was at the base of a steep slope. Workers had assessed the site for unstable rocks and danger trees only by looking up at the hillside from the old logging road below it. A few days before the incident, two blasts were detonated. However, the stability of the trees above the site was not re-assessed.

Two workers drilled the bore holes for the main blast. The next day, they loaded the holes with explosives. The supervisor came to help tie in the holes. Just before firing, a strong gust of wind suddenly blew through the quarry site. Two trees blew down from the steep slope. As the supervisor ran for cover, he was struck by one of the falling trees. He received fatal injuries.

• Ensure qualified personnel conduct a thorough hazard assessment of the terrain above roadways and quarry sites for soil stability and danger trees.
• Remove danger trees and blown-down trees above a worksite before work begins.
• Re-assess the stability of soil and trees after a blast.
• Provide written procedures for working in windy conditions, including how to measure winds and how to assess the wind hazard at a worksite.
• Ensure workers plan two escape routes that take into account the hazards at the site.