This is an excerpt from the 2018 “Chainsaw Training Limbing Accident Green Sheet“.
The instructor was diagnosed and treated at the trauma center for a concussion, head laceration, pneumothorax, broken ribs, and a C-5 vertebrae fracture.

Recreation of the position that FC1 was initially found in.
C-Faller field training on April 24, 2018 started at 0830 hours at CAL FIRE Bear Creek Fire Station in the Tulare Unit. All cadre members and students met for a daily safety briefing, IAP review, emergency procedures overview, identification of training groups and the completion of pertinent documentation (IIPP-6). Following the meeting, all cadre members and students proceeded up Balch Park Road approximately 21 miles to the training location. Once at the cut site, the predesignated groups proceeded to their predetermined cutting areas. Each group worked in areas that were pre-identified to ensure the safety of all personnel. Each group included an Instructor (C Certifier), a Proctor (C-Faller) and two to three students.
One group working at the top end of the training grounds had rotated, and was working one-on-one with their students. The Proctor (P1) had taken his students (S2) (S3) to an opposing slope adjacent to the other half of their group to cut. The area P1 identified provided him a clear view of the area where the other members of his group would be cutting, and was at a safe distance. The Instructor (FC1) from his group had identified a tree to be felled by the student (S1) under his tutelage. The tree was a large, dead Ponderosa pine at the toe of the slope. The tree measured 36 inches in diameter at breast height (DBH) and stood approximately 115 feet tall.
S1 assessed the tree and determined that it was to be felled up-slope to prevent it from obstructing a watercourse downslope, and FC1 agreed. FC1 and S1 discussed the hazards, the type of cut to be made, identified two escape routes, and cleared (swamped) the base of the tree for access and egress. Once a complete size-up of the tree was completed, and the identified escape routes were established and validated, FC1 directed S1 to begin his cut. S1 proceeded with his undercut, and readied himself to put his back cut into the tree. As is standard, and policy, S1 yelled, “back cut, up the hill” to alert the other members of his team, and any approaching personnel of his intention to fall the tree. After validating that he had been heard, S1 proceeded with his back cut.
The tree began to fall in the intended direction of the lay. During the fall, the top portion of the tree brushed the limbs of the oak tree (as FC1 and S1 had discussed) causing some oak limbs to break loose and fall to the ground ahead of the tree. As the tree came to rest on the slope, it split into three sections after contacting ground liter and terrain. The bottom section of the tree measured 45 feet in length at the break. The second section measured 47 feet and had landed atop the fallen oak limbs, and the third section (top of the tree) measured 23 feet, and was entangled at the base of the oak tree in a near-vertical position.
Once the tree was felled, S1, under the direct supervision of FC1 assessed the area for hazards such as hanging limbs or other collateral debris. S1 yelled “clear” after confirming that the oak limbs that had been brushed during the fall had been grounded. S1 planned to limb the felled tree and to flush cut the stump. FC1 advised S1 that he would assist in limbing the tree due to the length, and that he would start limbing from the first break in the tree toward the tip, and that S1 could start by cutting the stump flush, and limbing from the base up to the first break. S1 agreed, and FC1 proceeded to ascend the hill.
FC1 reached the first break in the felled tree and began to limb the pine. FC1, wearing full PPE including helmet, chaps, gloves, eye and hearing protection proceeded to limb the felled tree with his chain saw. FC1 had limbed approximately 24 feet of the felled tree when he encountered the large oak limbs that both he and S1 had witnessed get broken free from the oak tree by the falling pine. The limb had multiple forks and had come to rest beneath the felled pine tree in a near-vertical position. The limb measured 8 inches in diameter at the break with multiple forks ranging in size from 3-5 inches in diameter. The length of the limb, including the forks ranged from 5 to 17 feet in length. FC1 proceeded to assess the bind of each pine limb and cut it free with his chain saw.

Overview of the accident site (not to scale)
Unbeknownst to FC1, when the pine broke the oak limbs loose, and they fell ahead of the tree, the broken end of the oak limb contacted the ground first (likely due to weight) and stuck into the soil approximately 18 inches deep. This suspended the limb and the multiple forked branches of the limb into the air only to then be contacted by the falling pine as it came to rest on the ground. As the pine came to rest, it lay atop the broken end of the oak limb and placed the entire load of the felled pine onto the limbs. This downward pressure and the fact that the oak was a live tree allowed the limbs of the oak to bend under extreme pre-loaded tension and pressure. The felled pine tree limbs also directly contacted multiple sections of the oak limbs providing for additional tension.
As FC1 proceeded to limb the tree, he reached the oak limbs and with a single, partial cut released the full, pre-loaded tension of the upper portion of the oak limbs. This violent release of tension projected the limbs of the oak downward and outward, contacting FC1 on the left temple area of his helmet. This contact propelled FC1 backward off the felled pine, and downslope into a field of tree litter. FC1 was knocked unconscious by the initial impact.
P1, S2 and S3 all heard a loud “crack”, and since they were training within view of FC1 and S1, they each turned toward the sound. P1 immediately noted that FC1 was down, and could hear his chain saw idling. S2 and S3 were also able to see that FC1 was down, lying on his left side. P1 yelled FC1’s name as he proceeded to his location. P1 traversed approximately 500 feet across slope to reach FC1’s location. S2 and S3 also made their way to FC1.

Uphill view from the base of the tree showing the debris field
P1 was the first to arrive and found FC1 unconscious with agonal respirations and an actively bleeding head wound. At approximately 1429 hours, P1 reported “man down” to the designated C-Faller Course Safety Officer (SOF) via the assigned tactical frequency. With the report, the SOF instituted the “Incident within an incident” (IWI) protocol in order to collect accurate and sufficient information. P1 reported “traumatic head injuries with entrapment”. The SOF immediately contacted the CAL FIRE Tulare Unit ECC (Visalia) to report the injury. He ordered an air ambulance to the CAL FIRE Bear Creek Fire Station (pre-designated medivac location in the course IAP) and an Advanced Life Support (ALS) ground ambulance to the scene.
Meanwhile, P1 was not able to fully access FC1 because the oak limbs had fallen and was lying on top of FC1. P1 noted that there was still so much tension on the oak limbs that he was unable to lift them. By this time, S1 had made his way up the hill from the stump having heard the loud crack, as well. He assisted P1 in cutting the still-tensioned oak limbs from above FC1 so that they could further assess his injuries.
FC1 remained unconscious with agonal respirations as they completed an assessment of his injuries. Both S2 and S3 arrived to assist in the care of FC1. All personnel at the site worked to control the bleeding, and care for the injured FC1. After approximately 2-3 minutes, FC1 regained consciousness. He was confused, and became combative with the personnel working on him. Moments later, FC1 began to communicate with personnel, and started to breath normally.
Personnel worked to maintain cervical spine (c-spine) precautions, and to control the bleeding from his head wound. FC1 was placed in a c-collar. He again became combative, and kept attempting to get up. The personnel at the site continued to reassess FC1 for additional injuries. Due to the rural location, and extended ALS care and transport times, the SOF determined that FC1 would be extricated to the road above the accident site, and be transported in a CAL FIRE vehicle to meet up with responding ALS resources.
What “strikes you” most about this scenario?
Lessons about limbing?
or
Lessons about medical response capacity during training?
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