Date of incident: August 2013
Notice of incident number: 2013117640187
Employer: Manual tree falling company

Incident summary
A certified faller was falling an alder tree that was limb-tied with a second alder. As the first alder fell, the top of the second alder broke off. This treetop fell to the ground, striking the faller, who received fatal injuries.

Investigation conclusions

Cause

• Faller struck by falling treetop: As the first alder fell, the top of the second alder broke off 28 feet up from the ground. The faller sustained fatal injuries when the treetop struck him as it fell.

Underlying factors

• Pre-existing split created weak point: A pre-existing split in the trunk of the second alder, most likely the result of snow load or wind damage, allowed moisture into the trunk. As a result, mould and rot established itself, further weakening the tree.
• Failure to recognize hazard: The faller did not recognize the extent to which the two alders were limb-tied. Consequently, he did not anticipate that falling the first tree would place tension onto the trunk of the second. Most likely for this reason, he did not use the falling procedure recommended for limb-tied trees.
  
  In addition, the faller could not see the pre-existing split in the second alder, which was hidden by thick vegetation. This weak point was also on the side of the tree facing away from the faller. Finally, the healthy condition of the second alder above the pre-existing split may have led the faller to believe that this tree was sound.

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